COOL SEPTEMBER, WETTER AND SUNNIER THAN AVERAGE
Armagh Observatory, third October 2025: Armagh Observatory reviews that September 2025 was cooler, wetter, and sunnier than common. This was the wettest September at Armagh for 3 years.
The common temperature this month, outlined as half the common of the every day most and minimal temperatures, was 13.26 levels Celsius (55.9 levels Fahrenheit). That is roughly 0.72 C hotter than the 225-year long-term (1796-2020) common for September at Armagh (12.54 C) however 0.24 C cooler than the latest (1991-2020) 30-year common (13.50 C). The three warmest days, that’s, these with the best most air temperatures, had been an unremarkable 19.6 C on the 2nd, adopted by 19.3 C on the seventeenth, and 19.2 C on the sixth. The latest (1991-2020) 30-year common of the September every day temperature maxima at Armagh is roughly 17.3 C.
The best minimal air temperature, often the warmest night time, was 15.7 C, which occurred across the time of observations (09:00 GMT) on the sixth however following commonplace meteorological procedures this temperature minimal was attributed to the seventh. Equally, the second and third highest minimal air temperatures, each 13.1 C, occurred on the fifth and 18th however had been attributed to the sixth and nineteenth.
The bottom minimal air temperatures, or coolest nights, had been 3.3 C on the twenty fourth, adopted by 3.7 C on the twenty third and 4.1 C on the twenty second. The best day, or lowest most air temperature, was 14.2 C on the twenty first, adopted by 14.3 C on the twentieth and 15.0 C on the twenty seventh.
There have been six floor frosts this month, the bottom three of which had been -2.4 C on the twenty third, -1.8 C on the twenty second, and -1.4 C on the twenty fourth.
Complete precipitation was 98.55 mm (3.88 inches) together with three hint values, that’s, 98.4 mm if hint values are ignored. That is roughly 43% greater than the 183-year long-term (1838-2020) common September rainfall at Armagh (68.9 mm) and 52% greater than the latest (1991-2020) 30-year common (65.0 mm).
A vibrant gibbous moon was seen rising from behind cloud on the night of the 4th. Though there have been no named storms this month, the afternoon of the thirteenth was noteworthy for heavy rain together with hail and thunder, and for 2 partial rainbows. The common 09:00 GMT atmospheric strain diminished to imply sea stage this September, was roughly 1011 mbar. That is some 4 mbar decrease than the corresponding most up-to-date (1991-2020) 30-year common at Armagh (1015 mbar), indicating the impact of low-pressure climate techniques this month and an inclination for greater-than-average rainfall.
Regardless of a dry spell within the second half of the month this September was wetter than common with 18 rain days, that’s, meteorological days with complete precipitation better than or equal to 0.2 mm. The wettest day was the 14th with 23.5 mm of precipitation, adopted by the sixteenth with 15.4 mm and the 2nd with 9.4 mm. The 4 days starting the thirteenth produced greater than half the month’s complete rainfall.
The few final swallows of the season had been famous on the morning of the fifth, and a presumed pair of jays was seen near the met station on the morning of the twenty first. An unusually giant flock of roughly 45 gulls was noticed throughout the early night of the twenty third flying in a north-easterly course in 4 “V” formations. The next day, across the identical time, a equally giant flock of some 50 gulls was once more seen flying in the identical course.
With 130.4 hours of robust sunshine, this September had roughly 16% extra robust sunshine than the 140-year (1881-2020) long-term September common at Armagh (112.3 hours) and 14% greater than the latest (1991-2020) 30-year common (114.4 hours). The sunniest days had been 9.9 hours on the twenty third, adopted by 9.3 hours on the twenty first, and eight.9 hours on the twenty fifth.
These knowledge seek advice from 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
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