Summer weather Bonn’s summer was hot and dry
Bonn · The sun shone for a total of 786 hours from June to August – a new record.
Summer 2018 was too warm. So says the city of Bonn’s former chief statistician, Klaus Kosack, on the basis of his records and data from the Meteorological Institute of the University of Bonn. Bonn’s summers have become warmer by 0.9 degrees Celsius since 1895. However, the record set in 1947 was not broken.
The average temperature in Bonn throughout summer 2018 was 21.4 degrees Celsius (2017: 20.1 degrees Celsius). This was 3.5 degrees too warm when compared with the long-term average and was the second warmest summer since 1895. Only two summers in the last 20 years were below the long-term average (2000 and 2004). Each 2018 season so far has been above the long-term average. This year, only February and March were too cool. The warmest summer is still that of 1947. Summer 2018 failed to reach the temperatures of that summer of 71 years ago by only 0.3 degrees Celsius. The coolest summer was 62 years ago (1956).
Highest temperature was 39.1 degrees
The highest temperature of the year was 39.1 degrees Celsius on 7 August. The coolest summer day was on 26 August with 8.1 degrees Celsius. A total of 27 (2017: 13) hot days (with a maximum of over 30 degrees Celsius) and 62 (2017: 46) summer days (with a maximum of over 25 degrees Celsius) were recorded. Last summer, a maximum of 38.1 degrees was recorded in June and a minimum of 9.8 degrees Celsius in July. Another record: never in the preceding 123 years were so many summer and tropical days recorded. Bonn residents also had to sweat through six tropical nights (warmer than 20 degrees Celsius). In 2017 there were the same number of tropical nights.
Only June was too wet during summer 2018. A total of 145 litres of rain fell per square metre. – 225 litres would be normal for Bonn. This summer landed in spot 146 in Bonn’s 170-year rainfall history. The wettest summer to date was summer 2007, with 434 litres per square metre, followed by summer 2014.
The usual summer sunshine target of 583 hours was exceeded by 203 hours in Bonn (786 hours or 135 per cent). This is a new summer sunshine record. In 2017, the sun shone for 200 hours less. It shone for the longest in July (320 hours).
(Original text: kol. Translation: kc)
