The spring of 2017 has experienced an abnormally high mean temperature and few days of precipitation, according to a first climatological assessment prepared by the Royal Meteorological Institute (MRI) on Thursday. The month of May was particularly hot, with an average temperature of 15.5°. High temperatures were measured in Uccle in May. The mean temperature of the month was 15.5° (normally 13.6°), the mean of the maximum of 20.5° (18.1°) and the average of the minimum of 10.3° (9.2°). The first two values are “abnormally high”.
In the third decade, an exceptionally high mean temperature of 19.3° (normally 14.6°) was observed, breaking the previous record for the reference period of 1981-2016, which was 19.1° in 1992. An even greater value, however, was measured in 1922 at 20.3°.
For the whole of May, seven summer days were counted (maximum of 25° or more), for a normal of three days, that is to say a number equivalent to the record of 2008, as well as two tropical days (30° or more, compared to a normal of 0.2 days). On 29 May, mercury rose to 33.8° at Korbeek-Lo (Bierbeek – Flemish Brabant). It was the coolest on May 10, with up to -4.5° in Elsenborn (Bütgenbach).
Small quantities of precipitation have also been measured and the number of stormy days is considered normal. On the 11th, 12th, 18th and 27th to 29th, damage caused by rain, wind, hail or lightning was reported. The sun, for its part, shone in Uccle for 205 hours and 31 minutes, i.e. for a normal duration of time.
In general, the spring of 2017 experienced an “abnormally high” maximum mean temperature of 15.9° (normal of 14.2°) and little precipitation. “Precipitation totals across the country over the season are much lower than the seasonal norms”, comments the MRI. “They fluctuate between about 40% of the normal temperature in the Tournaisis up to about 70% in the Pays de Herve.”
If it snowed in March and April, the thickness of the snow remained very low. The most important level was reached on 1 March (5cm). Finally, the average wind speed was exceptionally low.