April 2018 was “abnormally hot” in Uccle, the Royal Meteorological Institute (IRM) says in its first climate report for the month. The average temperature was 13.0°C, whereas the norm is 9.8°C, while highs averaged 17.7°C as against a norm of 14.2°C. Both values were abnormally high. The average minimum temperature of 8.0°C, was exceptionally high compared to the norm of 5.3°C.
The highest temperature was on the 19th , when a maximum of 28.1°C was recorded. This was a high value, but still below the record of 28.7°C, registered in April 2007. The lowest minimum temperature –an abnormally high 2.5°C – was recorded on the 6th of April.
In the rest of the country, the highest temperature was also on the 19th. It was 31.2°C, registered in Bilzen, below the 1968 record of 31.4°C. in Liège. The lowest minimum was also on the 6th: -3.2°C in Elsenborn.
Where rainfall is concerned, 66.3mm of rain fell in 13 days in Uccle. The highest amount, 31.4 mm, was recorded on the 29th.
The monthly rainfall in the country fluctuated around the normal values for the month, ranging from 75% of the norm in the Borinage to about 140% in Kempen, with the thunderstorms on the 29th modifying a result that, until then, had been rather dry, the IRM highlighted.
There were 11 days of thunderstorms in April; the norm is 8.8 days.
There were also 171 hours and 33 minutes of sunlight and an average wind speed of 3.5 metres per second – both normal values – in Uccle.