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COVID-19 Data

Boulder County COVID-19 Data

  • The COVID-19 Case Data Summary and the COVID-19 Data Graphs will be updated on Monday, Wednesday, and Friday or the previous or following day if the day falls on a holiday.
  • Graphs will be adjusted every three months to ensure legibility.
  • Hospitalization data can be tracked through the Hospital Resource Summary located below, including available hospital resources and the number of people hospitalized.

Boulder County Public Health is notified of Boulder County residents who test positive for COVID-19. The information below only represents individuals who have tested positive or are considered probable. Students living in Boulder for school are considered residents.

A backlog of 604 cases from last November through May was added to the case totals on September 26.

Some data may be missing due to ongoing disease investigations and reporting delays.

Note: Boulder County Public Health has removed the Centers for Disease Control and Prevention (CDC) case rate per 100,000 of the population from this updated webpage as it is redundant to the information offered below in the graph titled, “7-Day Cumulative Number of New COVID-19 Cases per 100,000 Among Boulder County Residents.”

COVID-19 Data Graphs


This graph presents case counts by day rather than growth rates in total cases over time to increase the interpretation and actionability of the data.

The data represented in this graph only shows tests reported using the Electronic Laboratory Reporting system, which has included CU since Sept. 21, 2020. It does not include all labs testing for COVID-19. All other graphs on this webpage represent results from all labs.


The following information includes data about COVID-19 PCR (diagnostic) testing among Boulder County residents. Test results lag approximately three days from the time the test is conducted to when results are reported to the Colorado Department of Public Health and Environment (CDPHE).

BCPH calculates the percent positive is calculated as number of positive tests/number of total tests using data from the Electronic Laboratory Reporting (ELR) system, which does not include all labs testing for COVID-19 and does not include home test kits.

We are no longer displaying data on cases based on affiliation with a long term care facility.

Please note: The maximum number displayed on this graph does not represent a maximum number of resources in Boulder County but provides a point of reference and may change. Boulder County Public Health is unable to track the maximum number of resources available in Boulder County as this number shifts as hospitals make new beds available and staff levels fluctuate.

The Hospital Resources dashboard had previously displayed data regarding hospital capacity, ICU availability, ventilators, etc. Some of those indicators contained data that was found to be unreliable so we have removed them.

Race/Ethnicity & Municipality Data

We are currently unable to provide data regarding race/ethnicity and municipality.

COVID-19 Illness Data Summary

The information on this page is a summary of information about Boulder County residents who have tested positive for COVID-19 or are likely positive (Probable*) for COVID-19. The information is compiled and analyzed by Boulder County Public Health from disease investigations conducted with those who have tested positive for COVID-19 in the county combined with reports from the Colorado Department of Public Health and Environment, local hospitals, and the Boulder County Coroner.

Please note that details provided on the Colorado Department of Public Health and Environment website may not match this information due to delays in reporting. This information is subject to change at any time as disease investigations are ongoing. We have removed the recovery and transmission graphs due to incomplete data as a result of limited resources.

Reporting Methodology

Boulder County Public Health and CU Boulder are working to align our COVID data reporting methodology as much as possible. Review the reporting diagram for more information about how data is reported and shared.

Data Quality

The Boulder County Public Health Epidemiology and Surveillance Teams currently use our own data system in addition to the state data system to ensure we are reporting on the most up-to-date information. Each week, the Surveillance Team compares the state data to the Boulder County data to check if case investigations or interviews found that someone who was categorized as a Boulder County resident actually lives in another Colorado county. If this occurs, that person’s record is deleted from the Boulder County data system which is reflected in the data immediately. The team also looks for duplicate records and merges the records if duplicates are identified. Lastly, a check is performed to ensure that we are capturing all deaths reported to the state among people with COVID-19. Although we receive death information directly from the coroner and patient medical records, there have been instances where a death was reported to the state only and we discovered it through our quality assurance process.

About this Information

Individuals (cases) are counted on the day in which they are reported to the state data system, regardless of the day the investigation was completed.

Hospitalization information is determined during the first disease interview or through medical record review. Quality assurance processes may identify hospitalization after an interview occurred if medical record information can be located.

COVID-19 death data represents the total number of deaths reported among people who have tested positive or considered probable for COVID-19, even when COVID-19 may not have been the cause of death listed on the death certificate. This information is required by the CDC and is crucial for public health surveillance, as it provides more information about disease transmission and can help identify risk factors among all deaths across populations.

Deaths are identified through medical record review, notification by the Boulder County coroner, notification by a long-term care facility or other healthcare provider, and through information from the Colorado Department of Public Health and Environment including death certificates.

Boulder County Public Health reports deaths of individuals with COVID-19 who are Boulder County residents. The Boulder County Coroner reports all deaths that occur within the county, regardless of county of residence.

It may be deemed that a person is “Probable” (e.g. clinically diagnosed for COVID-19 or epidemiologically linked) if they came in close contact with a person who has tested positive for COVID-19 and was determined to be high risk during the disease investigation, AND they became symptomatic in the two weeks after contact with the ill person or the two weeks before, while they were infectious. Probable cases are determined using the CDC and Council of State and Territorial Epidemiologists case definition which includes both epidemiological and clinical criteria.

Testing data includes every individual for whom we have received a positive result for a diagnostic (PCR) test. Every individual is only counted once, even if they have multiple positive tests.

Individuals who received a positive antibody test are NOT considered confirmed cases. These individuals could be considered a probable case if they also meet clinical or epidemiological criteria. This represents less than 1% of Boulder County cases.

Testing data includes all tests among people who report a Boulder County residence regardless of where testing was received. Not all labs historically reported negative lab results but most labs now report both positive and negative test results.

The percent positive is calculated by dividing all positive PCR tests among Boulder County residents by all PCR tests performed among Boulder County residents since COVID-19 testing began. The 5-day average is the proportion of all tests that were positive over the last 5 days with complete data (3 days prior to the current day).

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Boulder County Public Health

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