Preliminary spring 2024 report outlines record rainfall and low sunshine

In the preliminary report, the meteorological service covers the period of 1 March to 21 May 2024, with data then being compared to the reference period to identify significant changes or outliers. MeteoLux, which is headquartered at Findel airport, found a number of deviations from the long-term weather norms, with notable variations in temperature, precipitation, and sunshine hours.

Temperatures up and down

The average temperature for the season stood at 10.4°C, which is 0.8°C higher than the 1991–2021 reference period. March saw an average temperature of 7.9°C, 2.2°C above the norm, while April's 9.5°C was slightly below average by 0.1°C. May, so far, has averaged 13.9°C, 0.4°C above the long-term mean. The highest temperature recorded was 24.7°C on 12 May, and the lowest was -1.2°C on 6 March.

This spring saw only three 'frost' days, which means minimum temperatures of 0°C, well below the usual 10.5 days, and six days of ground frost. There were no 'summer days', a term used to designate days with temperatures reaching 25°C or more, though typically, there would be around 3.5 such days in spring.

Record precipitation

Precipitation was significantly above average, with a total of 268.4 litres per square metre, surpassing the long-term average by 50%. March was particularly wet, receiving 81.4 l/sqm, 44% more than usual. April's rainfall was near average, with 48.4 l/sqm, just 2% below the norm. May, however, has been exceedingly wet, with 138.6 l/sqm recorded so far, 89% above the average.

The highest daily rainfall was 36.8 l/sqm on 17 May. Overall, there were 51 days of measurable precipitation, compared to the long-term average of 41.5 days. No snow days were recorded this spring, whereas typically, there would be around 2.6. Only two thunderstorm days occurred, less than the average of 5.5.

Sun a rare sight

Sunshine was in short supply, with only 352.2 hours recorded, 37.2% below the average of 560.9 hours. This makes it the second least sunny spring since records began in 1947, just behind 1983's record low of 300.4 hours. March had 105.5 hours of sunshine, 23% below average, while April saw 130.7 hours, 34% below normal. May has had 116.0 hours so far, 48.7% below the expected amount.

Fog days were also fewer than usual, with only four recorded this spring, compared to the long-term average of 7.7 days. Three of these occurred in March, none in April, and one in May to date.

In summary, Luxembourg's spring 2024 has been marked by higher temperatures, significantly more rainfall, and considerably less sunshine than usual, making it a season of notable weather deviations.