Luxembourg's Ministry of Agriculture, Viticulture and Rural Development has published a national meteorological analysis of 2021 compiled by AgriMeteo, the national meteorological service of the Administration of Technical Services for Agriculture (ASTA) of the Ministry.
Overall, 2021 (9.3°C) was cooler than the average (9.9°C) recorded during the 1991-2020 reference period. In terms of rainfall, a very slight rainfall deficit was recorded in the north of the country while, in the rest of the country, the amounts of rain were above multi-year standards. The year will be marked by a new temperature record (25.4°C) for the month of March in Clemency, as well as record bad weather in July (daily maximum of 105.8 mm rain at Godbrange) which caused catastrophic floods on 14-15 July 2021, seriously affecting many localities in Luxembourg.
Here follows a month-by-month meteorological review of 2021 for Luxembourg:
- January: snow all over the country, then thaw at the end of the month
The north of the country was covered in snow for most of January, with a maximum height of 13.6cm measured in Reuler on 1 January 2021. At the end of the month, the thaw took hold. January was rainier than normal.
- February: cold snap for St Valentine's weekend
February started off with relatively mild temperatures, then a surge of cold polar air swept through the country over the St Valentine's Day weekend. February saw below average rainfall, especially in the north.
- March: variable weather with record temperatures at the end of the month
The month of March presented itself with variable weather, with temperatures peaking above 25°C in Clemency, Obercorn, Remerschen and Remich at the end of the month. In terms of rainfall, there was a deficit in the north and in the south of the country, while the Moselle valley was close to average.
- April: too cold, too dry
April saw the return of polar air masses, with temperatures 3.0°C below average and freezing nights. While it rained in the first week, the rest of April saw a rain deficit across the country.
- May: too cold and too humid
The month of May started with freezing nights. Thereafter, temperatures remained below seasonal averages except for the last weekend. On the rainfall side, May recorded very heavy showers and accumulations.
- June: hot and stormy
June was warmer than average overall, with temperature peaks in the second and third week that resulted in localised thunderstorms and occasional excess precipitation.
- July: record bad weather considered a natural disaster and too cold temperatures
The month of July was marked by too low temperatures and a record level of precipitation (+193mm to the multi-year average recorded since 1984). On 14 - 15 July 2021, bad weather caused flooding on an unprecedented scale, seriously affecting many localities in Luxembourg. On 14 July, the 32 weather stations recorded between 62.6 mm of rain in Remerschen and a record daily maximum of 105.8 mm in Godbrange.
- August: too cold and slightly too dry
Temperatures in August were below seasonal averages. Despite regular rain, total precipitation remained slightly below normal over much of the country.
- September: hot and fairly dry weather
September was warmer than the benchmark average overall, with more pronounced temperature peaks in the first and last week. Across the country, the month was too dry, with a slightly larger rainfall deficit in the north.
- October: Aurora storm and slightly too cold weather
On 21 October 2021, storm Aurora blew over Luxembourg and the AgriMeteo station network recorded gusts between 70 and 90 km/h, with a maximum of 98 km/h at Eschdorf. October was slightly too cold, except in parts of the Moselle valley.
- November: too cold and too dry
In November, temperatures were clearly below seasonal averages. From 20 November 2021, a cold spell persisted in the Grand Duchy until the end of November, when the first snow was seen in the Oesling (6.6cm in Reuler). On the rainfall side, the level of precipitation was deficient throughout the country.
- December: too hot and too dry
Temperatures across the country turned freezing in December a few days before the Christmas holidays before rising to values well above year-end averages. While the first three weeks of the month were mainly dry, rain came in the last week of the year. However, totals remained below the multi-year average across the country.
The data come from the network of 32 automatic weather stations from all regions of Luxembourg. The values of four representative stations Asselborn (north), Clemency (southwest), Remich (Moselle valley) and Grevenmacher (Moselle valley) were compared with the mean values of the reference period 1991-2020.
Consequences for agriculture and viticulture
Favourable weather for fodder production, but difficult for cereals and rapeseed
Vegetation for all crops started very slowly due to low temperatures in early spring. But by the end of winter 2021, the winter crops sown in autumn 2020, especially cereals, were in very satisfactory condition. The excessive rainfall in May and July favoured the growth of meadows and pastures, as well as fodder crops such as corn silage. On the other hand, the growth and harvest of cereals and rapeseed were impacted by rainfall during these months, so that the yields were disappointing for these crops in 2021.
Bad weather of 14-15 July 2021 caused damage (€1,650,000) in the agricultural sector
The bad weather and floods of 14 and 15 July 2021 also caused significant damage to many farmers, wine growers and market gardeners. The Ministry of Agriculture, Viticulture and Rural Development processed 153 requests for financial assistance to compensate the affected farms (damage to buildings, damaged agricultural equipment and machinery, loss of fodder and damaged crops).
Late frosts without major consequences
Late frosts left their mark in orchards and vineyards, but the damage caused varied depending on the location of the orchard and the precocity of the varieties and grape varieties cultivated. As regards arboriculture and viticulture, the harvest was generally satisfactory, both for the quantity and for the quality of the fruits and grapes harvested.
Warm and fairly dry weather in autumn, favourable to the ripening of the grapes
In the Moselle, the dry weather, hot days and cool nights favoured the ripening of the grapes and the development of aroma precursors in September. At the start of the harvest, on 27 November 2021, winegrowers were rewarded with ripe grapes of good quality and in normal quantities. The grapes harvested are promising for a fruity and refreshing vintage with moderate alcohol contents.
All data recorded by the 32 ASTA weather stations are published on www.agrimeteo.lu.