I don't know how many people visit the Netherlands, but I often see tourists dressed in T-shirts and Bermuda Shorts wandering around even though there's gale blowing outside coupled with torrential downpours.
So I figure that people simply don't check the weather forecast beforehand presumably because they assume it's going to be in Dutch.
But the Dutch Meteorological site has a very good English weather site which includes a rain radar which shows exactly where it's raining, the intensity of it and which direction it's heading in: http://knmi.nl/index_en.html
Here's an interpretation of the colours:
- Pale grey = light drizzle
- Dark grey = shower
- Pink = heavy rain
- Red = torrential downpour
- Black = cloudburst
Also useful for the rest of Europe is the Meteo Alarm site with its clickable map: http://meteoalarm.eu/