Weekly COVID-19 County Level of Community Transmission as Originally Posted

Note:
March 23, 2023: Due to technical difficulties, Indiana's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 23, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 23, 2023: Due to technical difficulties, Indiana's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 23, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 23, 2023: Due to data processing delays, the case rates for all Mississippi counties will be reported as 0 in the data released on March 23, 2023. Therefore, the COVID-19 Community Transmission metrics for all Mississippi counties may be underestimated and should be interpreted with caution. Updates to the state-level case counts were not affected by this issue.    

March 23, 2023: CDC is working together with colleagues from the Texas Department of State Health Services to accurately reflect the results of a 2021 reconciliation process for COVID-19 cases. As of the data collection deadline, a solution was not able to be finalized. Texas’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 23, 2023, release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution.  

March 23, 2023: Due to maintenance to Arkansas’s COVID-19 dashboard, aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 23, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 23, 2023: Due to a decrease reported in cumulative case counts, case rates for Richmond City, Virginia will be reported as 0 in the March 23, 2023, weekly release. Therefore, the COVID-19 Community Transmission levels for these counties may be underestimated and should be interpreted with caution. 

Beginning on October 20, 2022, CDC retrieves aggregate case and death data from jurisdictional and state partners weekly instead of daily. This public use dataset contains weekly community transmission levels data for all available counties and jurisdictions as displayed on COVID Data Tracker's County View since October 20, 2022. Each week, the dataset is appended to contain the most recent week's data and is updated on Thursdays, typically by 8pm ET. Historical corrections are not made to these data if new case or testing information become available. A separate file is made available here (Weekly COVID-19 County Level of Community Transmission Historical Changes) if historically updated data are desired.

Related data
CDC provides the public with two active versions of COVID-19 county-level community transmission level data: this dataset with the levels as originally posted (Weekly Originally Posted dataset), updated weekly with the most recent week’s data since October 20, 2022, and a historical dataset with the county-level transmission data from January 22, 2020 (Weekly Historical Changes dataset).

Methods for calculating county level of community transmission indicator
The County Level of Community Transmission indicator uses two metrics: (1) total new COVID-19 cases per 100,000 persons in the last 7 days and (2) percentage of positive SARS-CoV-2 diagnostic nucleic acid amplification tests (NAAT) in the last 7 days. For each of these metrics, CDC classifies transmission values as low, moderate, substantial, or high (below and here). If the values for each of these two metrics differ (e.g., one indicates moderate and the other low), then the higher of the two should be used for decision-making.

CDC core metrics of and thresholds for community transmission levels of SARS-CoV-2
Total New Case Rate Metric: "New cases per 100,000 persons in the past 7 days" is calculated by adding the number of new cases in the county (or other administrative level) in the last 7 days divided by the population in the county (or other administrative level) and multiplying by 100,000. "New cases per 100,000 persons in the past 7 days" is considered to have a transmission level of Low (0-9.99); Moderate (10.00-49.99); Substantial (50.00-99.99); and High (greater than or equal to 100.00).

Test Percent Positivity Metric: "Percentage of positive NAAT in the past 7 days" is calculated by dividing the number of positive tests in the county (or other administrative level) during the last 7 days by the total number of tests conducted over the last 7 days. "Percentage of positive NAAT in the past 7 days" is considered to have a transmission level of Low (less than 5.00); Moderate (5.00-7.99); Substantial (8.00-9.99); and High (greater than or equal to 10.00).

If the two metrics suggest different transmission levels, the higher level is selected.

The reported transmission categories include:

Low Transmission Threshold: Counties with fewer than 10 total cases per 100,000 population in the past 7 days, and a NAAT percent test positivity in the past 7 days below 5%;

Moderate Transmission Threshold: Counties with 10-49 total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 5.0-7.99%;

Substantial Transmission Threshold: Counties with 50-99 total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 8.0-9.99%;

High Transmission Threshold: Counties with 100 or more total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 10.0% or greater.

Blank: total new cases in the past 7 days are not reported (county data known to be unavailable) and the percentage of positive NAATs tests during the past 7 days (blank) are not reported.

The data in this dataset are considered provisional by CDC and are subject to change until the data are reconciled and verified with the state and territorial data providers.

This dataset is created using CDC’s Policy on Public Health Research and Nonresearch Data Management and Access.

Archived data
CDC has archived two prior versions of these datasets. Both versions contain the same 7 data elements reflecting community transmission levels for all available counties and jurisdictions; however, the datasets were updated daily. The archived datasets can be found here:

October 20, 2022: Due to the Mississippi case data dashboard not being updated this week, case rates for all Mississippi counties are reported as 0 in the COVID-19 Community Transmission Level data released on October 20, 2022. This could lead to the COVID-19 Community Transmission Levels metrics for Mississippi counties being underestimated; therefore, they should be interpreted with caution. 

October 20, 2022: Due to a data reporting error, the case rate for Philadelphia County, Pennsylvania is lower than expected in the COVID-19 Community Transmission Level data released on October 20, 2022. This could lead to the COVID-19 Community Transmission Level for Philadelphia County being underestimated; therefore, it should be interpreted with caution. 

October 28, 2022: Due to a data processing error, case rates for Kentucky appear higher than expected in the weekly release on October 28, 2022. Therefore, the COVID-19 Community Transmission Levels metrics for Kentucky counties may be overestimated and should be interpreted with caution. 

November 3, 2022: Due to a reporting cadence issue, case rates for Missouri counties are calculated based on 11 days’ worth of case count data in the COVID-19 Community Transmission Level data released on November 3, 2022, instead of the customary 7 days’ worth of data. This could lead to the COVID-19 Community Transmission Levels metrics for Missouri counties being overestimated; therefore, they should be interpreted with caution.

November 10, 2022: Due to a reporting cadence change, case rates for Alabama counties are calculated based on 13 days’ worth of case count data in the COVID-19 Community Transmission Level data released on November 10, 2022, instead of the customary 7 days’ worth of data. This could lead to the COVID-19 Community Transmission Levels metrics for Alabama counties being overestimated; therefore, they should be interpreted with caution.

November 10, 2022: Per the request of the jurisdiction, cases among non-residents have been removed from all Hawaii county totals throughout the entire time series. Cumulative case counts reported by CDC will no longer match Hawaii’s COVID-19 Dashboard, which still includes non-resident cases. 

November 10, 2022: Due to a reporting cadence issue, case rates for all Mississippi counties are reported as 0 in the COVID-19 Community Transmission data released on November 10, 2022. This could lead to the COVID-19 Community Transmission Levels metrics for Mississippi counties being underestimated; therefore, they should be interpreted with caution. 

November 10, 2022: In the COVID-19 Community Transmission Level data released on November 10, 2022, multiple municipalities in Puerto Rico are reporting higher than expected increases in case counts. CDC is working with territory officials to verify the data submitted. 

November 25, 2022: Due to a reporting cadence change for the Thanksgiving holiday, case rates for all Ohio counties are calculated based on 13 days' worth of case counts in the COVID-19 Community Transmission Level data released on November 25, 2022, instead of the customary 7 days’ worth of data. This could lead to the COVID-19 Community Transmission Levels metrics for all Ohio counties being overestimated; therefore, they should be interpreted with caution.

November 25, 2022: Due to the Thanksgiving holiday, CDC did not receive updated case data from the following jurisdictions: Rhode Island and Mississippi. As a result, case rates for all counties within these jurisdictions are reported as 0 in the COVID-19 Community Transmission Level Data released on November 25, 2022. This could lead to the COVID-19 Community Transmission Levels metrics being underestimated within these jurisdictions; therefore, they should be interpreted with caution.

December 1, 2022: Due to a data processing error, case rates for California appear lower than expected in the December 1, 2022, weekly release. Therefore, the COVID-19 Community Transmission Levels metrics for California counties may be underestimated and should be interpreted with caution.

December 1, 2022: Due to cadence changes over the Thanksgiving holiday, case rates for all Ohio counties are reported as 0 in the COVID-19 Community Transmission Level data released on December 1, 2022. Therefore, the COVID-19 Community Transmission Levels may be underestimated and should be interpreted with caution. 

December 1, 2022: Due to a reporting cadence issue, case rates for all Mississippi counties are calculated based on 14 days’ worth of case count data in the Community Transmission information released on December 1, 2022, instead of the customary 7 days’ worth of case count data. Therefore, the weekly case rates for all counties will be overestimated, which could affect COVID-19 Community Transmission Level classification and should be interpreted with caution.  

December 8, 2022: Due to a statewide network issue, CDC did not receive updated case data from Georgia. As a result, case metrics will be reported as 0 in the December 8, 2022, weekly release. COVID-19 Community Transmission Levels metrics may be underestimated and should be interpreted with caution.

December 22, 2022: Due to an internal revision process, case rates for some Tennessee counties may appear higher than expected in the December 22, 2022, weekly release. Therefore, the COVID-19 Community Transmission Levels metrics for some Tennessee counties may be overestimated and should be interpreted with caution.

December 22, 2022: Due to reporting of a backlog of historic COVID-19 cases, case rates for some Louisiana counties will appear higher than expected in the December 22, 2022, weekly release. Therefore, the COVID-19 Community Transmission Levels metrics for some Louisiana counties may be overestimated and should be interpreted with caution.

December 29, 2022: Due to technical difficulties, county data from Alabama could not be incorporated via standard practices. As a result, case and death metrics will be reported as 0 in the December 29, 2022, weekly release. Therefore, the COVID-19 Community Transmission Levels metrics for Alabama counties will be underestimated and should be interpreted with caution.

December 29, 2022: Due to the holidays, CDC did not receive updated case data from the following jurisdictions: District of Columbia, North Carolina, and Utah. As a result, case rates for all counties within these jurisdictions will be reported as 0 in the COVID-19 Community Transmission Level Data released on December 29, 2022. This could lead to the COVID-19 Community Transmission Levels being underestimated within these jurisdictions; therefore, they should be interpreted with caution.

January 5, 2023: Due to a reporting cadence issue, case rates for all Alabama counties will be calculated based on 14 days’ worth of case count data in the COVID-19 Community Transmission Level information released on January 5, 2023, instead of the customary 7 days’ worth of case count data. Therefore, the weekly case rates will be overestimated, which could affect counties’ COVID-19 Community Transmission Level classification and should be interpreted with caution.

January 5, 2023: Due to technical difficulties at the source, case rates for all Colorado counties will be reported as 0 in the COVID-19 Community Transmission data released on January 5, 2023. This could lead to the COVID-19 Community Transmission Levels for Colorado counties being underestimated; therefore, they should be interpreted with caution.

January 5, 2023: Due to North Carolina’s holiday reporting cadence, aggregate case data will contain 14 days’ worth of data instead of the customary 7 days. As a result, case metrics will appear higher than expected in the January 5, 2023, weekly release. COVID-19 Community Transmission metrics may be overestimated and should be interpreted with caution.

January 5, 2023: Due to a data processing issue, case rates for all Nevada counties will be reported as 0 in the COVID-19 Community Transmission data released on January 5, 2023. This could lead to the COVID-19 Community Transmission Levels for Nevada counties being underestimated; therefore, they should be interpreted with caution.

January 12, 2023: Due to a reporting cadence issue, Illinois’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the January 12, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

January 12, 2023: Due to technical difficulties, Indiana’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the January 12, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

January 12, 2023: Due to technical difficulties, aggregate county-level case data in the January 12, 2023, weekly release will be reported as 0 for the following counties in Texas: Dallas County, Tom Green County, and Travis County. Therefore, COVID-19 Community Transmission metrics for those counties may be underestimated and should be interpreted with caution. 

January 12, 2023: Due to data processing delays, Mississippi’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the January 12, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

January 19, 2023: Due to a reporting cadence issue, Mississippi’s aggregate case data will be calculated based on 14 days’ worth of data instead of the customary 7 days in the January 19, 2023, weekly release. Therefore, COVID-19 Community Transmission metrics may be overestimated and should be interpreted with caution.

January 26, 2023: Due to a reporting backlog of historic COVID-19 cases, case rates for two Michigan counties (Livingston and Washtenaw) were higher than expected in the January 19, 2023 weekly release. Community Transmission metrics for those counties may be overestimated and should be interpreted with caution.

January 26, 2023: Due to a backlog of historic COVID-19 cases being reported this week, aggregate case counts in Charlotte County and Sarasota County, Florida, will appear higher than expected in the January 26, 2023 weekly release. Community Transmission metrics for those counties may be overestimated and should be interpreted with caution.

January 26, 2023: Due to data processing delays, Mississippi’s aggregate case data will be reported as 0 in the weekly release posted on January 26, 2023. As a result, case metrics will appear lower than expected, and the Community Transmission metrics for all Mississippi counties may be underestimated and should be interpreted with caution.

February 2, 2023: As of the data collection deadline, CDC observed an abnormally large increase in aggregate COVID-19 cases reported for Washington State. In response, totals for new cases released on February 2, 2023, have been displayed as zero at county level until the issue is addressed with state officials. Because case rates will be reported as zero for the current week, the COVID-19 Community Transmission Levels for all counties in Washington State may be underestimated and should be interpreted with caution. CDC is working with state officials to address the issue.

February 2, 2023: Due to a decrease reported in cumulative case counts, case rates for several Wyoming counties will be reported as 0 in the February 2, 2023, weekly release. Therefore, the COVID-19 Community Transmission Levels for several Wyoming counties may be underestimated and should be interpreted with caution. CDC is working with state officials to verify the data submitted. 

February 2, 2023: Due to a backlog of historic COVID-19 cases being reported this week, case rates for East Baton Rouge Parish, Louisiana will appear higher than expected in the data released on February 2, 2023. This could lead to the COVID-19 Community Transmission Level for this county being overestimated, and it should be interpreted with caution. 

February 9, 2023: Due to data processing delays, the case rates for all Mississippi counties will be reported as 0 in the COVID-19 Community Transmission Level data released on February 9, 2023. Therefore, the COVID-19 Community Transmission Levels for all Mississippi counties may be underestimated and should be interpreted with caution.

February 9, 2023: Due to a decrease reported in cumulative case counts, the case rate for Richmond City, Virginia, will be reported as 0 in the February 9, 2023, release. Therefore, the COVID-19 Community Transmission Level for this county may be underestimated and should be interpreted with caution. CDC is working with state officials to verify the data submitted.

February 16, 2023: Due to data processing delays, Utah’s aggregate case data will be reported as 0 in the weekly release posted on February 16, 2023. As a result, case metrics will appear lower than expected. Community Transmission metrics may be underestimated and should be interpreted with caution. 

February 16, 2023: Due to a reporting cadence change, Maine’s aggregate case data may contain less than the customary 7 days’ worth of data in the February 16, 2023, release. Therefore, Community Transmission metrics may be underestimated and should be interpreted with caution. 

February 16, 2023: Due to a suspected data reporting cadence change, the case rates for all New Mexico counties may be lower than expected in the data released on February 16, 2023. This may lead to the COVID-19 Community Transmission Levels for all New Mexico counties being underestimated; therefore, they should be interpreted with caution. CDC is working with state officials to verify the data submitted. 

February 23, 2023: Due to data processing delays, Hawaii’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the February 23, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

February 23, 2023: Due to data processing delays, the case rates for all Mississippi counties will be reported as 0 in the data released on February 23, 2023. Therefore, the COVID-19 Community Transmission metrics for all Mississippi counties may be underestimated and should be interpreted with caution.

February 23, 2023: Due to a backlog of historic COVID-19 cases being reported this week, case rates for Maricopa County and Pinal County, Arizona will appear higher than expected in the weekly data released on February 23, 2023. This could lead to the COVID-19 Community Transmission metrics for these two counties being overestimated and they should be interpreted with caution. 

February 23, 2023: Due to a backlog of historic COVID-19 cases being reported this week, case rates for several Georgia counties will appear higher than expected in the weekly data released on February 23, 2023. This could lead to the COVID-19 Community Transmission metrics for several Georgia counties being overestimated and they should be interpreted with caution. 

March 2, 2023: Due to a decrease reported in cumulative case counts, the case rate for Richmond City, Virginia will be reported as 0 in the March 2, 2023, weekly release. Therefore, the COVID-19 Community Transmission levels for Richmond City may be underestimated and should be interpreted with caution. 

March 2, 2023: Due to a data processing error, the case rate for Yamhill County, Oregon will be reported as 0 in the March 2, 2023, weekly release. Therefore, the COVID-19 Community Transmission metrics for Yamhill County may be underestimated and should be interpreted with caution.  

March 9, 2023: Due to data processing delays, Utah's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 9, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 9, 2023: Due to technical difficulties, Washington State's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 9, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 9, 2023: Due to technical difficulties, Florida's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 9, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 9, 2023: Due to a decrease reported in cumulative case counts, case rates for Richmond City, Virginia will be reported as 0 in the March 9, 2023, weekly release. Therefore, the COVID-19 Community Transmission levels for these counties may be underestimated and should be interpreted with caution.  

March 16, 2023: In coordination with Florida health officials, CDC completed a historical correction to address a technical issue affecting aggregate COVID-19 cases reported by Florida between November 2022 and March 2023.

March 16, 2023: Due to technical difficulties, Arkansas’s aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 16, 2023, weekly release. Therefore, COVID-19 Community transmission metrics may be underestimated and should be interpreted with caution.

March 16, 2023: Due to potential technical difficulties that are being reviewed with the state, Texas's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 16, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 16, 2023: Due to a decrease reported in cumulative case counts, case rates for Richmond City, Virginia, will be reported as 0 in the March 16, 2023, weekly release. Therefore, the COVID-19 Community Transmission levels for these counties may be underestimated and should be interpreted with caution. 

March 16, 2023: Due to a backlog of historic COVID-19 cases being reported this week, the case rate for Washoe County, NV, will appear higher than expected in the weekly data released on March 16, 2023. Therefore, the COVID-19 Community Transmission levels for these counties may be underestimated and should be interpreted with caution. 

March 16, 2023: Due to technical difficulties, Indiana's aggregate case data will be reported as 0. As a result, case metrics will appear lower than expected in the March 16, 2023, weekly release. COVID-19 Community Transmission metrics may be underestimated and should be interpreted with caution. 

March 16, 2023: Due to data processing delays, the case rates for all Mississippi counties will be reported as 0 in the weekly data released on March 16, 2023. Therefore, the COVID-19 Community Transmission metrics for all Mississippi counties may be underestimated and should be interpreted with caution. Updates to the state-level case counts were not affected by this issue.