Health

• Covid-19: Covid-19 Decay Index
• Pollen concentrations: Pollen concentrations | Pollen Warning

Covid-19 Decay Index

These indices indicate the time that has to pass until a certain percentage of the present COVID-19 concentration decays. Recent investigations showed that the decay of COVID-19 was enhanced by either increased humidity or temperature (Biryukov et al., 2020). Additionally, there is also a dependence on sunlight, which has an impact on the potential for aerosol transmission of COVID-19 (Schuit et al., 2020). The indices are based on the numbers of the SARS-CoV-2 Airborne Calculator published by Homeland Security.

• Half-life of the virus outdoors in minutes:

  covid_half_life:min

• Time in minutes until 90% of the virus died:

  covid_decay_90:min

• Time in minutes until 99% of the virus died:

  covid_decay_99:min

Examples:

• The chart below shows the 90 % decay time of COVID-19 for North America, where the influece of heat in the south-western United States on the virus' lifetime can be seen:

  

• Below is a time series that shows the 90 % and 99 % decay times of COVID-19 as well as the half life time for Zurich:

  

  Current Situation:
  https://api.meteomatics.com/2025-04-17T00:00:00ZP15D:PT1H/covid_half_life:min,covid_decay_90:min,covid_decay_99:min/47.36882,8.5374/html

References

• Biryukov J, Boydston JA, Dunning RA, Yeager JJ, Wood S, Reese AL, Ferris A, Miller D, Weaver W, Zeitouni NE, Phillips A, Freeburger D, Hooper I, Ratnesar-Shumate S, Yolitz J, Krause M, Williams G, Dawson DG, Herzog A, Dabisch P, Wahl V, Hevey MC, Altamura LA. 2020. Increasing temperature and relative humidity accelerates inactivation of SARS-CoV2 on surfaces. mSphere 5:e00441-20. https://journals.asm.org/doi/10.1128/mSphere.00441-20
• Michael Schuit, Shanna Ratnesar-Shumate, Jason Yolitz, Gregory Williams, Wade Weaver, Brian Green, David Miller, Melissa Krause, Katie Beck, Stewart Wood, Brian Holland, Jordan Bohannon, Denise Freeburger, Idris Hooper, Jennifer Biryukov, Louis A Altamura, Victoria Wahl, Michael Hevey, Paul Dabisch, Airborne SARS-CoV-2 Is Rapidly Inactivated by Simulated Sunlight, The Journal of Infectious Diseases, Volume 222, Issue 4, 15 August 2020, Pages 564–571, https://academic.oup.com/jid/article/222/4/564/5856149
• https://www.dhs.gov/science-and-technology/sars-airborne-calculator

Pollen Concentrations

Pollen concentrations are available in grains per cubic meter.

birch_pollen:grainsm3

grass_pollen:grainsm3

olive_pollen:grainsm3

ragweed_pollen:grainsm3

pollen:grainsm3 gives the total pollen concentration in grains per cubic meter.

Examples:

• The grass pollen concentration in July 2019 in Florence, Italy:

  

  Current situation:
  https://api.meteomatics.com/2025-04-17T00Z--2025-04-20T00Z:PT1H/grass_pollen:grainsm3/43.7800148,11.2059487/html
• Part of the output as CSV:

  validdate;grass_pollen:grainsm3
  2019-07-20T00:00:00Z;8.0
  2019-07-20T01:00:00Z;7.3
  2019-07-20T02:00:00Z;6.2
  2019-07-20T03:00:00Z;5.9
  2019-07-20T04:00:00Z;5.3
  2019-07-20T05:00:00Z;7.6
  2019-07-20T06:00:00Z;16.3
  2019-07-20T07:00:00Z;12.6
  2019-07-20T08:00:00Z;11.1
  2019-07-20T09:00:00Z;8.9
  2019-07-20T10:00:00Z;7.6
  2019-07-20T11:00:00Z;7.0
  2019-07-20T12:00:00Z;7.3
  2019-07-20T13:00:00Z;8.1
  2019-07-20T14:00:00Z;9.5

Pollen Warning

The pollen warning returns warning levels for different types of pollen loads according to the DWD.

<type>_pollen_warning:idx

Available types of pollen: hazel, alder, ash, birch, grass, rye, mugwort, ragweed, max(maximum pollen load)

Warning	Description
0	No pollen load
0.5	No or small pollen load
1	Small pollen load
1.5	Small or moderate pollen load
2	Moderate pollen load
2.5	Moderate or high pollen load
3	High pollen load

Examples:

• Grass pollen load in spring 2021:

  

• Current situation:
  https://api.meteomatics.com/2025-04-17T12ZP1D:PT1H/grass_pollen_warning:idx/51.23693,10.13906/html