The rain in Spain

The rain in Spain falls mainly on the....weekend.

Apologies to Frederick Loewe and Alan Jay Lerner who wrote the original song for My Fair Lady, but they may have been on to something. It seems that the rain really does fall not on the plain - but at the weekend.

Scientists have known for some time that human activity can drive local weather patterns. That's because sooty particles and other pollutants can influence air circulation as they are heated by the sun, and can help to seed clouds. And of course we produce more pollution during the week.

Although the phenomenon is well documented in the US, China and Japan it was thought that European weather systems were too complicated to show the effect clearly. But now a team led Arturo Sanchez-Lorenzo at the University of Barcelona is claiming to have found similar patterns over Spain and much of western Europe.

The research, published in the Journal of Geophysical Research Letters and reported in next week's New Scientist, shows more rain falling during the week in the winter, while in summer months the pattern is reversed.

So now you know why it always seems to look so sunny out of the office window, and why that tantalising promise never holds until you're free to enjoy it at the weekend. Well, that's the theory anyway....and the forecast for the weekend? It's going to bucket down, naturally.