RECORD-BREAKING JULY. DRIEST FOR AT LEAST 190 YEARS, EQUAL HIGHEST PRESSURE, AND MUCH WARMER AND SUNNIER THAN AVERAGE
Armagh Observatory, 4th August 2026: Armagh Observatory reports that this July 2026 was the driest July on record at Armagh, that is, since daily rainfall measurements began at the Observatory in 1836. This month was also much warmer than average, the sixth warmest July on record at Armagh, and the tenth sunniest.
Total precipitation was an exceptionally low 3.4 mm (0.13 inches) including six trace values, that is, 3.1 mm if trace values are ignored. This was just 4.6% of the 183-year (1838–2020) long-term average July precipitation at Armagh (73.4mm) and 4.9% of the slightly lower most recent (1991–2020) 30-year July average (69.0mm).
The wettest day was the 31st with 1.4 mm of rainfall, followed by 0.6 mm on both the 1st and 29th. This month saw a total of just five rain days, that is, days with at least 0.2 mm of precipitation. The several driest Julys at Armagh are now July 2026 (3.4mm), July 1878 (4.7mm), July 1863 (6.2mm), July 2000 (13.3mm), July 1898 (14.3mm), and July 1982 and 1983 (both 15.2mm).
Low rainfall is often associated with high atmospheric pressure, and July 2026 was no exception. The highest daily 09:00 GMT pressure at Armagh reduced to mean sea level was 1031.9 mbar on the 21st, well down the list of highest July atmospheric pressures at Armagh, but the monthly average pressure (approximately 1022 mbar) was 7 mbar higher than the corresponding 170-year (1851–2020) July long-term average (1015 mbar).
This was the highest average July atmospheric pressure on record at Armagh, shared with July 1989, 1968, 1955, and 1911. These months also had lower-than-average precipitation, but because in each case the run of dry weather was broken by one or more wet days none were exceptionally dry. To take July 1955 as an example, this month also had 5 rain days, but total precipitation was 51.1 mm dominated by rainfall in the first three days of the month, with 43.7 mm on the 3rd, the third-wettest July day on record at Armagh.
This illustrates the vagaries of rainfall, which although changing very little on average over the 190 years that it has been measured daily at Armagh, does fluctuate very significantly from place to place and both from year to year and from one month to another. To mix metaphors, precipitation is characterised by feast and famine, with dry places often close to wet ones and dry periods often following wet spells and vice versa.
July 2026 was also another very warm month at Armagh, with an average temperature of 17.65 degrees Celsius (63.8 Fahrenheit). This is approximately 2.78 C warmer than the 225-year long-term (1796–2020) average at Armagh (14.87C) and 1.93C warmer than the most recent (1991–2020) 30-year July average (15.72C). This July was the sixth warmest on record at Armagh and the warmest for five years, that is, since July 2021 (mean temperature 17.88C).
The average of the daily maximum air temperatures was 22.43C, approximately 2.77C warmer than the corresponding most recent (1991–2020) 30-year July average (19.66C) and ranking sixth in the list of highest average maximum July temperatures at Armagh. Similarly, the average of the daily minimum air temperatures was 12.87C, which is 1.10C warmer than the corresponding most recent (1991–2020) 30-year July average (11.77C) and sixth in the list of highest average minimum air temperatures at Armagh.
The warmest days (highest maximum air temperatures) were 27.7C on the 15th, followed by 27.6C on the 16th, and 27.1C on the 8th. The 15th, although a very warm day, was neither exceptionally hot for a warm July day at Armagh nor the warmest day of the year. The latter is still the 25th of June 2026 (29.8C). This warm July also included the second heat wave of the year, namely the 14th to the 17th of July inclusive, each day of which achieved maximum temperatures at least 25.0C. This is the second year in a row that heat waves have been recorded at Armagh in both June and July.
The coolest days (lowest maximum air temperatures) were a relatively mild 17.2C on the 1st, followed by 17.9C on the 2nd and 18.6C on the 31st, indicating how this July was book-ended at the beginning and end of the month by more changeable weather. The warmest night (usually the highest minimum air temperature) was 16.2C at approximately 11:26 GMT on the 27th and therefore attributed to the 28th, followed by 16.1C on the 29th, and 14.5C on the 5th. The coolest night (lowest minimum air temperature) was 8.9C on the 19th, followed by 9.6C on the 31st, and 10.2C on the 30th. Not surprisingly, there were no air frosts or ground frosts. The lowest grass-minimum temperatures were 1.2C on the 19th, 2.3C on the 31st, and 3.3C on the 30th.
This July was also sunnier than average, with a total of 194.9 hours of strong sunshine recorded by the Observatory’s Campbell-Stokes sunshine recorder. This is approximately 143% of the 140-year long-term (1881–2020) July average at Armagh (135.9 hours) and nearly 145% of the most recent (1991–2020) 30-year July average (134.8 hours). This was the sunniest July at Armagh for thirteen years, that is, since July 2013 (228.1 hours of strong sunshine) and the tenth sunniest July at Armagh since daily sunshine records began in 1880. The sunniest day was the 13th with 14.1 hours of strong sunshine, followed by the 14th and 16th, both with 13.8 hours.
These data refer to observations at Armagh Observatory, which has been recording the weather at Armagh since 1795.
For further information, please contact:
Professor Mark E. Bailey
Emeritus Director of Armagh Observatory
Armagh Observatory and Planetarium
College Hill
Armagh
BT61 9DG
Tel: 028-3752-2928
E-mail: mark.bailey@armagh.ac.uk
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