Covid-19 virus spreading rate and humidity

Dit artikel in het Nederlands (this article in Dutch)

American scientists ( M. Sajadi et al. ) have demonstrated an inherent relationship between the rate at which the Covid-19 virus can spread and the air humidity. The microbiologist Dr. Alan Evangelista also describes a clear relationship between the humidity of the air and the rate at which the virus can spread.

In their article, the American scientists indicate that the optimal conditions for the rapid spread of the virus at a specific humidity range between 3 grams and 6 grams per kilogram.

For example, on Feb. 22, this value at 2 p.m. in Seoul, Tehran, Bergamo, Madrid, and Seattle was indeed between 4 and 5.5. In Wuhan 1 month earlier, that value was 5.8. By comparison on February 22, that value was above 8 in Miami and above 14 in Taipei, Hong Kong and Singapore.

In this article Maurice de Hond has listed those findings.

Calculator Specific Humidity

This is a calculator in which you can enter the temperature in Celcius of Fahrenheit, and the relative humidity in percent. These actuals are listed in almost all weather forecasts.

The result is the all-important "specific humidity" expressed in grams per kilogram. Based on that study by M. Sajadi et al., it is indicated whether this value indicates a more or less favorable situation for the virus to spread quickly.

Please appreciate that the article is based on hypotheses (although very plausible) and that the limit values ​​3 g / kg and 6 g / kg are not absolute.

Placing the calculator on other websites

This calculator can be used on other websites. Add this code to your website:

<div id="covid-19-calculator-app" lang="en" defaulttemperature="C"></div> <script type="text/javascript" src=""> </script>

Credits to: Maurice de Hond, Michael Michel, Menno Zweistra, Alvin Gerona, Rob Captijn en Dennis Brouwer.