Cold and Very Wet
Temperatures
The average maximum temperature during May 2021 in Horsholm was 15.3 Celsius, and that was around 2.5 degrees below normal for the time of year. The average minimum temperature was 6.3 Celsius, and that was less than 0.5 degrees below the monthly normal.
The highest temperature recorded during the month was 24.0 Celsius on the 10th, but there were only 3 other days with maxima above 20 Celsius. On the 9th, a high of 21.3 Celsius occurred, and the last 2 days of the month had maxima of 22.9 and 23.2 Celsius respectively. There were only 3 other days, the 24th and the 29th, when the temperature rose above 17 Celsius. On most days (19) the maximum temperature was between 12 and 17 Celsius (54-63F), but on 5 consecutive days, beginning on the 3rd, the temperature failed to reach 12 Celsius, with 3 of these colder days, the 4th, 5th and 6th, having maxima below 10 Celsius. The coldest day was the 6th with a high of 8.6 Celsius, but the previous day was only 0.2 Celsius less cold.
There was only 1 mild night during May, that was on the 10th when 14.3 Celsius was recorded. Only 2 other nights, the 12th and 13th, had minima above 10 Celsius. Both nights had lows of 10.8 Celsius. On many occasions (15) the temperature fell to between 4 and 8 Celsius, but there were some lower values. The 24th had a minimum of 3.9 Celsius, but this was the only reading below 4 Celsius after the 8th. Between the 1st and 8th, there were 7 occasions with minima below 4 Celsius, including the first nights of May when the temperature fell below 3 Celsius. However, the only measurement below 2 Celsius was on the 2nd when 0.7 Celsius was recorded.
Frost
No air frosts were recorded during the month.
Rain
There were 78.8 millimetres of rain recorded during May, and that was about 3 times the monthly average. Across Denmark as a whole, it was the wettest May since 1983, and the second wettest since records began in 1847. Measurable precipitation fell on 19 days, and that was 8 days above average, and wet days (when 1 millimetre or more of rain was measured) numbered 17 days, and that was 10 days above average for the month. the first 2 days of the month were dry, but each day during the following week had rain, with daily totals which included 11.8 millimetres on the 4th, and 5.2 millimetres on the 5th. There were only 2 further dry days before the 18th, and sometimes rain was quite heavy. On the 13th, a fall of 7.2 millimetres occurred, with 5.0 and 7.8 millimetres recorded on the 16th and 17th respectively. After 3 dry days, rain occurred on all bar 1 day between the 21st and 27th. Much of the rain was light, but 9.4 millimetres were measured on the 25th. The last 4 days of the month were dry.
Hail
No hail was observed in this part of Horsholm.
Thunder
There was thunder heard on 3 days during May. On the 13th, thunder occurred early in the afternoon, with an early afternoon thunderstorm also occurring on the 17th. The last thunderstorm was early in the evening on the 21st.
Snow
No sleet or snow was observed in this part of Horsholm.
Wind
It was a very cyclonic month but with almost two-thirds of the winds arriving from between southeast and southwest. Often this would be a warm direction, but skies were frequently cloudy, and the rain or showers kept the temperatures depressed. On 5 days, northwesterly winds were dominant, and unusually, at the end of the month, they ushered in some of the month’s highest temperatures. Generally, winds were gentle or moderate, but fresh breezes occurred early in the month and during the fourth week of May.
Fog
There was no fog observed in Horsholm during the month.