Extreme Rainfall Trends In Holland
By Paul Homewood
I have taken a look at extreme daily rainfall in the UK in a number of posts recently, for instance here.
However, one of the longest running meteorological records is at De Bilt in Holland, and KNMI have daily rainfall data in their archive which dates back to 1906. What do these tell us about extreme rainfall?
Figure 1 shows the top 50 rainfall days, equating to 34mm.
The wettest day was in October 2013, with 63.9mm. However, this was only 1mm more than fell in August 1917. As with the UK, we see that the 1970’s and 80’s had a marked absence of really wet days, but I am not sure of there is anything significantly different between recent years and earlier in the 20thC.
We can also check the decadal distribution of these days. Again, we see that really wet days were just as common in the 1940’s and 60’s as lately.
One other useful chart that KNMI produce is for max hourly precipitation each day. This goes back to 1951.
We often hear it claimed that global warming is making short term rainfall, such as hourly, heavier. The above chart shows this not to be true. The one outstanding event was in June 1953.
There may be a case for arguing that such events have become slightly more common in the last 20 years or so, but they are certainly not getting more intense.