Last month was the warmest September in Belgium since records began. Throughout the month, several daily temperature records were broken.
After a rainy start to this summer, the weather significantly improved in Belgium, reaching a peak by the time the school holidays were over in September. The Royal Meteorological Institute (RMI) confirmed that weather-wise, it was an above-average month.
"September 2023 was an absolute record month in terms of temperature," the Belgian weather service noted in a statement on Sunday. It was the warmest September since records began in 1833.
The average temperature over the entire month clocked in at 18.8°C, while normally, this is 15.2°C in September. The record for the average maximum temperature was 24°C, compared to the 19.5°C normally recorded at this time of year.
For the first time since observations of heat waves began in 1892, such a phenomenon was recorded in Uccle (from 4 to 11 September). Meanwhile, as many as six tropical days (30°C or warmer) took place last month, four days more than previous record years (two days in September in 1906, 1911, 1919, 1949 and 2020).
In terms of number of summer days (25°C and warmer), the record of nine days dating back to 2006 was also equalled. Furthermore, the first 10 days of the month will go down in history as the warmest recorded in September since observations began.
From 7.9°C to 31.9°C
When it comes to the average minimum temperature (measurements of this started in 1982), the absolute record from 1999 was also equalled: 14.1°C on average, or 2.8°C warmer than normal.
In Uccle, temperatures last month ranged from the lowest point of 7.9°C, measured on 24 September, to the highest point of 31.9°C, on 10 September. "This last value is the third highest since observations began in 1892," RMI noted.
The highest recorded temperature in the whole country was in Zulzeke in East Flanders, where the temperature soared to 33.8°C on 9 September, while the lowest minimum temperature was recorded on 24 September in Elsenborn (Bütgen- bach), where it dropped to 0.3°C.
Credit: Belga/ Nicolas Maeterlinck
One of the only normal values recorded in September was the precipitation amount: 64.3 mm of rain fell, compared to 65.3 mm on average during this month. However, in Uccle, this amount fell in just eight days, while normally this level of precipitation appears in 14.1 days.
"The record for the current reference period remains at 6 days (1997), and 2014 and 2021 also saw fewer precipitation days (seven days)," RMI explained.
September was also an extremely sunny month: the sun shone for a total of 194 hours and 8 minutes in Uccle, compared to 154 hours and 28 minutes on average in the past. With just four days of cloudy conditions, the number of cloudy to overcast days clocked in at a new record low.
For now, September's heat seems to be continuing, as on the first day of October, temperatures reached 24°C in Uccle.
