June set a new record

June 2026 has been officially recognised as the hottest month in the history of meteorological observations in Luxembourg. The average temperature for the month was 19.9°C, narrowly surpassing the previous historical highs of 19.8°C recorded in 2003 and 2023. The climate norm for the period from 1991 to 2020 is set at 16.7°C.

Weather conditions fluctuated sharply throughout the month. The first ten days of June were unusually cool: the average temperature was 13.9°C, which is 2.2°C below the established norm. However, between 11 and 20 June, temperatures rose sharply to an average of 19°C.

The extreme heat, which set the final record for the month, occurred during the last ten days. From 21 to 30 June, the average temperature reached 26.7°C, 9°C above the norm. During this period, maximum temperatures reached 33.3°C, whilst minimum temperatures were around 20.1°C. The Findel weather station recorded eleven consecutive days with temperatures above 30°C. In addition, meteorologists recorded six tropical nights – a climatic phenomenon in which the night-time temperature does not fall below 20°C. The highlight of this period came on 26 June, when a new all-time temperature record for the first month of summer was set: 38.2°C.

These temperature anomalies were accompanied by a significant shortfall in rainfall. Over the month, 59.5 litres of water per square metre fell, compared with the normal figure of 73 litres. At the same time, there was an excess of sunshine – 263.3 hours, which is approximately 22 hours above the long-term average. Consequently, June 2026 topped the list of the hottest Junes, surpassing the figures for 2003, 2023, 2019 and 1976, and signalled a further consolidation of the trend towards extreme temperature rises in early summer.