May was the warmest month of May in three centuries. In the current climate, a comparable extremely warm month of May occurs once every 60 years.

A total of 13 summer days (25.0 ° C or higher) were measured. This is the highest number since 1901. The average temperature in De Bilt was 16.4 ° C, the long-term average is 13.1 ° C.

De Bilt had its first tropical day of 2018 on May 29th

The month started cool, but quickly became hot in the summer. The last days of the month it was sweltering and in the nights it was not cooler than 18 degrees. De Bilt had its first tropical day of 2018 (30.0 ° C or higher) on May 29th. The highest temperature 31.9 ° C was measured that day in Lelystad. The measurements in Lelystad are currently being influenced by large-scale construction work at the airport, where the measuring station is located. The sunniest was in the northern coastal area with 326 hours of sun on Terschelling. The sun shone the least in Zeeland with about 260 hours. This is special because in May, as in the rest of the coast, it is generally sunnier than inland. On average, there was less rainfall in the Netherlands than normal. Due to the often diffuse character of the precipitation, the regional differences were large. In the wettest places about 100 millimeters fell, on Terschelling only 15 millimeters. A large part of the monthly amount of precipitation fell during heavy thunderstorms in the last week. Due to thunderstorms, KNMI issued code orange three times: on May 27 for Limburg, on May 29 for almost the entire country and on May 31 for the northern half.

Gentle and very sunny spring
The spring of 2018 comes at a (shared) third place of softest springs since 1901. The season was also very sunny.

The average temperature in De Bilt was 11.0 ° C one and a half degrees above the long-term average of 9.5 ° C. March was cold, April very mild and may be the warmest month of May in three centuries. The lowest temperature was reached on the first day of spring in New Beerta: -9.6 ° C. Easter Sunday, April 1st, was at a grade of 7 cool, even colder than the last Christmas day. Then followed a long period with mild to very mild weather. The first summer day (25.0 ° C or higher) was on April 19. Normally there are no summer days in April, now there were three.

This spring the normal amount of precipitation fell and it was very sunny

This spring the normal amount of precipitation fell. Wilhelminadorp was the wettest KNMI station with approximately 273 millimeters. The least rain fell in Hupsel: 116 millimeters. This season was very sunny. The sunniest was on the north coast with on Terschelling 682 hours of sunshine. In the southwest the sun shone the least, in Westdorpe there were 534 hours of sunshine.