Is Belgium experiencing the second driest spring ever?
Over the past few days, Belgium has enjoyed sunny weather and tropical temperatures. Later this week, the average temperature will rise to 30°C, possibly accompanied by heavy clouds and a chance of thunderstorms, as is the case in tropical countries. According to Rozemien De Troch, climate scientist at the Royal Meteorological Institute (RMI), this weather is highly unusual.
"The average temperature in Uccle (where the weather station is located) for May is currently 14.8°C, which is around the normal value," De Troch says. For the period 1991-2020 the average temperature was 13.9°C. "However, the average maximum temperature in Uccle for May is currently 2°C above the normal value." The current average maximum temperature is 20.4°C. During the period 1991-2020 it was 18.4°C.
For Uccle and the rest of Belgium, the very low level of precipitation is remarkable.
"In Uccle, total precipitation for the spring months is currently 40.3 mm. During the spring of 1976, 69 mm was recorded in Uccle."
De Troch points out that the spring of 2022 will be even drier than that of 1976 in terms of precipitation quantity alone, and will be the second driest spring in Uccle since measurements began.
The spring of 1893 was the driest, with 37.6 mm of precipitation. However, rain is expected in the second half of the week. In any case, the spring in Uccle will end with a level of rainfall very close to that of 1976.
"In terms of drought, the standardised precipitation index compared this spring with the past 30 years and recorded a 'dry' to an 'extremely dry' season for Belgium."
"Drought is a complex phenomenon determined by several parameters," De Troch explains. "In addition to precipitation quantity, for example, evaporation, surface runoff, water management and other elements play an important role. But in general we can say that in Europe and in Belgium global warming increases the risk of drought and makes it worse."
In recent decades, experts have observed a downward trend in spring precipitation. For Uccle in particular, this means a decrease of about 4 percent since 1961. Moreover, the droughts that have occurred in spring in recent years, with the exception of last spring (2021), correspond to what climate models expect for our region in the future.
As temperatures rise, warmer air can hold more water vapour before becoming saturated, and it will take longer for rain to fall. Once it does rain, however, the intensity may be greater.
© BELGA PHOTO Kurt Desplenter - Illustration picture shows floods on Monday 06 December 2021 in Merkem, after days of heavy rainfall in the West-Vlaanderen province.