Too warm and too wet

April weather summary: first record warmth, then cold

The bottom line: April 2024 was too warm and too wet, while the sun shone in its usual range.(Bild: Irina Mikhailichenko - stock.adobe.com)

April 2024 was divided into two parts: In the first half, temperatures reached record levels and were around ten to 15 degrees above average for this time of year. Then a cold snap set in, which ultimately brought the month to an unspectacular 13th place in the ranking of the warmest April months in the lowlands.

"In the first half of April, over 100 of the 280 weather stations set new heat records for April. These included weather stations with very long measurement series, both in the lowlands and in the mountains," says climatologist Alexander Orlik from Geosphere Austria.

15 degrees at 2117 meters above sea level
"For example, the Innsbruck University weather station recorded the highest April temperature in the series of measurements since 1877 at 30.7 degrees and the Graz University weather station recorded the highest April temperature in the series of measurements since 1884 at 30.5 degrees. At 20.9 degrees, the weather station on the Feuerkogel recorded the highest April value in the series of measurements since 1930 and at 15 degrees on the Villacher Alpe, at 2117 meters above sea level, it was the highest April temperature in the series of measurements since 1926."

The fact that there is still snow below 700 meters above sea level in the second half of April is relatively common and occurs about once every one to two years.

Klimatologe Alexander Orlik

In mid-April, a cold snap ended the summery weather phase and in some regions it snowed down to low altitudes. For example, there were five centimetres of snow in Lienz on 23 April, two centimetres in Klagenfurt and Zeltweg and one centimetre in Reichenau an der Rax. In contrast to the exceptional warmth in the first half of the month, such cold spells occur quite frequently in April. 

The wintry weather phase also ensured that the snow depth above 1500 meters above sea level largely corresponded to the climate average towards the end of the month. Overall, April 2024 was 1.2 degrees above the average for the 1991 to 2020 climate period in Austria's lowlands and 1.8 degrees above the average in the mountains. Compared to the 1961 to 1990 climate period, which was not yet as severely affected by global warming, April 2024 was 2.7 degrees above average in the lowlands and 3.4 degrees above average in the mountains.

More precipitation recorded
The amount of precipitation in April 2024 was 15 percent above the long-term average. At one percent above average, the number of hours of sunshine was almost exactly in line with the long-term average.

Early pollen count, followed by massive frost damage 
The very warm start to spring over long stretches meant that the plants developed around two to four weeks earlier. The start of flowering for lilacs (80-year measurement series), apples (84-year measurement series) and pears (64-year measurement series) was even the earliest of the respective measurement series.

However, the cold snap slowed down development considerably and caused massive frost damage to vines and fruit crops in some regions.