German researchers from the University of Karlsruhe have now proven what all of us knew by intuition:
The weekends receive more bad weather then the weekdays!
Seriously, here's the link (in German though)!
They analyzed the weather data from 12 German weather stations collected during the years 1991 to 1995, a total of 6.3 Million readings, which isn't bad statistically.
The average amount of sunshine on Mondays exceeds the Saturday sunshine by 15 minutes. And the weekend cloud cover surpasses the cloud cover during the week by 10%. It also rains more during the weekend, with rain intensity increasing by 15 % during the course of the week.
This phenomenon was evident at all 12 weather stations and was independent from the location e.g. within cities or out in the countryside.
OK, the drawback is that they have only measured but not explained it. They suppose it has something to do with the dust particles produced by e.g. burning fossil energy which happens more during the week when everybody is working than on the weekends when everyone is at home.
Now, is this good news or bad news for us birders?
Hard to say, depends on how good we can manage to adjust to it:
Hawks which are dependant on thermals e.g. should be chased after during the week, but if you're hoping for a warbler "fall-out" at Point Pelee during this year's spring migration, better get there on a weekend!