How to use Covid to measure Meteo

The graph shows the number of days needed to double the number of infected people (with the current infection evolution). Clearly, the higher, the better. 

During the summer, the doubling delay was growing almost linearly, which was very good. In September, in most European countries, the situation rapidly deteriorated. The weather was very cold. About a week ago, the temperature started to go up - and the doubling delay quickly followed. It will be interesting to see what happens when weather becomes cold again.

(The cause of much worse evolution in Czechia has probably nothing to do with weather.)

Winter is Coming !