Summer of 2011 one of the wettest in Dutch history

Clouds hid the sun

DE BILT - The 360 millimetres of rain in the Netherlands since the start of Summer 2011 will earn it very likely a place in the top-three of wettest summers ever. Particularly July delivered the country an amount of precipitation rivaled only in July 1966. The amount of precipitation in August is considered to be ‘fairly normal’.

A wet summer tends to reduce the periods of sunshine. By August 24, the Netherlands on average (it can vary from region to region) saw only about 150 hours of it, compared to the 700 hours recorded in 2010 and 690 hours in 2009.

Fewer hours of sunshine are not conducive for setting high temperature records. August brought just seven summer days (with an average temperature of more than 25 degrees Celsius) and two tropical ones (warmer than 30 degrees Celsius) compared to 21 summer days and 3.8 tropical ones in an average summer.

Warnings

The only thing about normal about this summer was the overall average temperature of 16.5 degrees Celsius compared to 17 degrees in an average summer. June rated a 0.5 degree above average, July 2 degrees below average, August fairly normal at 17.5 degrees on average.

There was plenty by way of extreme weather however. The Dutch weather service KNMI issued five weather warnings this summer, four of them in the week of August 17. Weather analysts call this very rare, hardly ever occurring in the far more unstable winter seasons.