March 20, 2020

Temperature Forecasts, Cherry Blossoms and Covid-19

To start on a positive note, the Cherry Blossoms are in full bloom on the UW Campus, with the visual effect enhanced by the beautiful, sunny weather.  (I should note that the UW is not encouraging folks to visit the blosssoms in person).

There is a lot of interest in the temperature/coronavirus relationship and what the weather forecasts suggest.

During the past several weeks there have been several papers submitted (but not yet reviewed) suggesting that coronavirus flourishes for daily mean temperatures roughly from 32F to 55F.  Warmer than that, the virus has problems.

The temperature map for the past month suggests that the only area of the U.S. that has been at sufficiently warm (14C--57F or more) to slow up the virus was the southeast U.S. (see below).

Unfortunately, the latest forecasts do not offer warm-temperature virus relief for much of the country during the next week.  Let me show that by presenting the 11 AM PDT temperatures for the next few days.  Look for the blue, yellow, orange and red colors for virus-poor conditions.

Saturday morning: SE U.S. is good.  Not so good for the NW and NE.

Monday--same thing,  but improved  (warm) condition in most of Texas.
 By Wednesday, warmer temperatures are over the SE, the central plains, and up into the Carolinas.
 Fast forwarding to next Sunday (March 29th), little improvement for the NW and NE.
The bottom line is that mother nature is not giving most of us the warm temperatures needed to suppress the virus    But April is not far away.

And if you want some good news, the coronavirus testing at the University of Washington (Med School's Virology department) is now finding a stabilization in the number of positive evaluations (see graphic below).   Another good piece of news is that the overwhelming number of tests are negative (folks are getting sick from the flu and other illnesses).

UW Virology have been extreme heroes during this event, providing COVID-19 testing when CDC was failing, as well as revving up to do thousands of tests per day.  Makes one proud to be a husky.  Check out their web site---and consider providing a donation for their excellent work.


  1. With abundance of sunlight and uv help temperature and humidity should be a non influencer for those who leave their prison cell of home.

  2. Thumbs up - thanks - for all the good work being done at UW. 'Appreciate the update :)


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