MARVELLOUS MAY: SUNNIEST ON RECORD, MUCH WARMER, DRIER THAN AVERAGE. SUNNIEST AND WARMEST SPRING ON RECORD AND DRIER THAN AVERAGE
Armagh Observatory, sixth June 2025: Armagh Observatory studies that Could 2025, with 285.4 hours of sturdy sunshine, was the sunniest Could on report at Armagh. Additionally, following the record-breaking heat Could 2024 (common temperature roughly 13.9 C) and the sooner historic report Could 1809 (13.8 C), this Could, with a imply temperature of roughly 13.2 C, was a lot hotter than common, the equal third warmest Could on report at Armagh. The month was additionally drier than common, with complete precipitation lower than two-thirds the typical at Armagh.
Taking the three months March, April, and Could collectively, spring 2025 was the sunniest (617.1 hours of sturdy sunshine) and the warmest (common temperature 10.7 C) at Armagh on report, and likewise drier than common.
With a median temperature of 13.2 C this Could was the third warmest Could on report at Armagh, shared with Could 1848, Could 2017, and Could 2008. Nonetheless, though the typical most temperature every day was boosted by sturdy sunshine, there have been no exceptionally heat days. The three warmest days, that’s, these with the very best most temperatures, have been the twenty first (23.2 C), the 18th (23.0 C), and the sixteenth (22.7 C). The thirtieth of April (most temperature 23.4 C) stays the warmest day of the yr up to now at Armagh and guarantees to carry this place as much as no less than the center of June.
The month-to-month common of the day by day temperature maxima this Could was 19.0 C. That is roughly 3.7 C hotter than the 176-year (1844-2020) long-term common day by day most temperature for Could at Armagh (15.3 C) and three.1 C hotter than the corresponding (1991-2020) 30-year common. This was the very best common day by day most temperature for Could at Armagh for 177 years, that’s, because the record-breaking Could 1848 with a corresponding common of roughly 19.2 C.
For comparability, the typical of the day by day temperature minima was 7.36 C. That is roughly 1.08 C hotter than the corresponding 176-year (1844-2020) long-term common for Could at Armagh (6.28 C) and 0.36 C hotter than the newest (1991-2020) 30-year common (7.00 C).
These variations spotlight the results of largely clear skies this Could, particularly elevating daytime temperatures and decreasing these at night time. Conversely, though the earlier Could 2024 reported a report excessive common temperature for the month (13.9 C), that month was duller than common with the excessive common temperature extra strongly influenced by heat nights than scorching days. Such variations present the significance of the poorly understood phenomenon of cloudiness in figuring out a month’s common temperature.
The three coolest days (lowest day by day most temperatures) have been the 4th (14.2 C), the twenty sixth (14.8 C), and the twenty fifth and twenty seventh (each 15.1 C). The warmest night time (highest minimal air temperature) was the thirtieth (13.5 C), adopted by the thirty first (13.1 C) and the twenty fourth (12.9 C). The best night time (lowest minimal air temperature) was the fifth (1.0 C), adopted by the sixth (2.4 C) and the ninth (3.7 C).
An extra consequence of comparatively clear skies this Could is that there was a comparatively giant variety of nights with floor frost, that’s, nights when the grass minimal temperature fell to lower than or equal to zero levels Celsius. The three hardest floor frosts occurred on the fifth, ninth, and eighth of Could, with respective grass-minimum temperatures of -6.2 C, -2.9 C and -2.4 C. There have been no air frosts, promising this yr fruit crop.
Whole precipitation this Could was 38.25 mm (1.51 inches) together with one hint worth, that’s, 38.2 mm if hint values are ignored. That is roughly 65% of the Could common at Armagh (roughly 58 mm) and continues an fascinating end result that almost all latest Mays at Armagh, now eight of the final ten, have been drier than common. The wettest day was the twenty eighth with 7.4 mm of precipitation, adopted by the eleventh with 5.9 mm and the twenty fourth with 5.7 mm.
The observer famous the primary swallow of the season on the first of Could and the primary swifts on the seventh.
This Could was dominated by higher-than-average atmospheric strain, the typical 09:00 GMT strain at Armagh (decreased to imply sea stage) being roughly 1020.1 mbar. That is 4.7 mbar increased than the 170-year (1851-2020) long-term common 09:00 GMT Could strain at Armagh (1015.4 mbar) and 4.1 mbar increased than the newest (1991-2020) 30-year Could common (1016.0 mbar). There have been no gales this month.
Thunder was heard throughout the night of the twentieth when localised thundery downpours, some with giant hailstones, have been reported from neighbouring areas round Armagh. On the Observatory, nonetheless, solely raindrops have been reported, and no precipitation recorded. A double rainbow was noticed on the night of the twenty fourth.
Could 2025 reported a report quantity of sturdy sunshine, particularly 285.4 hours, which is almost 62% greater than the 140-year (1881-2020) long-term Could common at Armagh (176.4 hours) and 60% greater than the newest (1991-2020) 30-year common (178.8 hours). The 4 sunniest Mays at Armagh at the moment are Could 2025 (285.4 hours), Could 1901 (254.1 hours), Could 1935 (251.6 hours), and Could 2017 (250.2 hours). Could 2025 is now additionally the sunniest month at Armagh, the 4 following sunniest months being June 1887 (263.7 hours), June 1940 (256.0 hours), Could 1901 (254.1 hours), and June 1949 (252.9 hours). The sunniest day was the thirteenth with 14.9 hours of sturdy sunshine, adopted by 14.3 hours on the 14th, and 14.2 hours on each the fifteenth and seventeenth.
Taking the three months March, April and Could collectively, the meteorological spring 2025 was drier than common and each the sunniest and the warmest spring on report at Armagh. These information of sturdy sunshine and temperature discuss with observations at Armagh that started in 1880 and 1795 respectively.
The imply spring temperature was an exceptionally heat 10.74 C. That is 2.62 C hotter than the 225-year (1795-2020) common spring temperature at Armagh (8.12 C) and 1.75 C hotter than the newest (1991-2020) 30-year spring common (8.99 C). The 5 warmest springs at Armagh at the moment are 2025 (10.7 C), 2017 and 2024 (each 10.2 C), and 1945 and 2011 (each 10.0 C).
Whole spring precipitation was 120.9 mm together with 6 hint values, that’s, 120.6 mm if hint values are ignored. That is roughly 72% of the 183-year (1838-2020) long-term common spring precipitation at Armagh (167.0 mm) and practically 70% of the newest (1991-2020) 30-year common (173.8 mm). Rainfall totals at Armagh differ considerably from month to month and from yr to yr, however on common present little or no change over practically 200 years.
Every of the meteorological spring months (March, April, and Could) have been sunnier or a lot sunnier than common. This led to spring 2025 being exceptionally sunny. The 617.1 hours of sturdy sunshine set a brand new report for spring sunshine at Armagh, roughly 45% greater than the 140-year (1881-2020) long-term spring common at Armagh (424.4 hours) and 43% greater than the newest (1991-2020) 30-year spring common (431.6 hours). The 4 sunniest springs at Armagh at the moment are spring 2025 (617.1 hours), spring 2020 (567.4 hours), spring 2007 (554.3 hours), and spring 2008 (547.6 hours).
These knowledge discuss with observations at Armagh Observatory, which has been recording the climate at Armagh since 1795.
For additional data, please contact:
Professor Mark E. Bailey
Emeritus Director of Armagh Observatory
Armagh Observatory and Planetarium
School Hill
Armagh
BT61 9DG
Tel: 028-3752-2928
E-mail: mark.bailey@armagh.ac.uk
