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Estimated Airborne Decay of SARS-CoV-2 (virus that causes COVID-19)

Estimated Airborne Decay of SARS-CoV-2 (virus that causes COVID-19)

under a range of temperatures, relative humidity, and UV index

Use the sliders to select the UV index, temperature and relative humidity of interest. Information on how long SARS-CoV-2 would be expected to remain stable in aerosols (airborne) will be displayed in the table below. Users can find the environmental conditions for a specific location by accessing general weather resources online.

SARS-CoV-2 Airborne Decay Calculator





°F / 23.9 °C




COVID Stability:

% Virus Decay Minutes Hours
50% (half-life): 11.32 0.47
90%: 150.39 6.27
99%: 225.59 9.40



  • Minimizing person-to-person spread of SARS-CoV-2 is one of the main ways to reduce the impact of COVID-19.
  • Transmission is believed to occur through respiratory droplets produced by talking, coughing and sneezing. Contact with contaminated surfaces and objects may also contribute to spread.
  • Increased temperature and relative humidity cause a minimal increase in SARS-CoV-2 decay, but the addition of simulated sunlight causes rapid decay of the virus in aerosol.
  • These data have been used to develop a predictive model to estimate virus decay in aerosols under a limited range of environmental conditions.
  • The data that supports the decay of SARS-CoV-2 with simulated sunlight (UV) is published in the Journal of Infectious Diseases and can be found here.

Model Caveats

Graphic showing UV index and Relative Humidity rapid decay per minute model

  • It should be noted that in order to fully assess the hazard posed by aerosols containing SARS-CoV-2, additional information is needed, including how much infectious virus is shed by infected individuals into the air, and the amount of virus that needs to be inhaled to cause infection.
  • The tool is valid for the following ranges of conditions: 50-86°F, 20-70% relative humidity, and UV indices of 0-10.

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