Mean daily temperature of summer 2023 in Clemency (red) compared to the reference period 1991−2020 (blue); the range is defined by the average of the minima and maxima of the mean daily temperature (in grey); Credit: AgriMeteo / ASTA

A new weather report has confirmed that summer 2023 in Luxembourg was marked by extreme variations in temperature and precipitation between the first and second half of the season.

As summer 2023 draws to a close, AgriMeteo, the national meteorological service of the Administration of Technical Agricultural Services (ASTA) of Luxembourg's Ministry of Agriculture, Viticulture and Rural Development, has published its weather analysis for the period from 1 June to 31 August 2023.

The analysis looked at the network of 39 automatic weather stations across the Grand Duchy. The three-month values of four representative stations, namely Asselborn (north), Clemency (south-west), Remich (Moselle) and Luxembourg City (centre), were compared with the averages of the reference period 1991-2020.

According to the analysis, summer 2023 was marked by extreme variations in temperature and precipitation between the first and second half of the summer, and in particular by the onset of drought in June, followed by excessive rainfall from mid-July.

In terms of temperatures, the summer was warmer than normal, with average temperatures up to +1.4°C in Luxembourg City. For rainfall, the results are mixed depending on the region. Whilst there was little rain in Remich, the weather stations of Asselborn, Luxembourg City and Clémency all recorded a surplus of rain.

June: Too hot and too dry

With anomalies between +2.6°C and +3.6°C, the month of June was the sixth hottest June since records began in 1838. Rainfall was low across the country, with variations between -55.4 mm and -40.3mm.

July: Slightly too cold with excessive rain

The month of July was marked by average temperatures which were a little colder than normal, down to -0.7°C, with the exception of Luxembourg City, where the average temperature was +0.5°C higher than normal. The precipitation level gradually increased from 71.7 mm to 108.2 mm.

August: Cool and rainy

Throughout the Grand Duchy, the beginning of August was relatively cold and rainy. From mid-August, temperatures rose and then fell again. The month was colder than normal (anomalies down to -0.7°C), with an exception in Luxembourg City. The rain was excessive in the whole of the Grand Duchy, up to +54.7 mm.