Summer 2026 burns all previous weather records

 

'Summer' refers to the meteorological summer - the three months of June, July and August, unless otherwise stated. The figures all come from the University of Reading's Atmospheric Observatory. Daily weather records have been made at the university since 1908.

Summer 2026 was by far the hottest summer on the university's long record. The mean daily temperature (the average of the observed daily minimum and maximum temperatures) for June, July and August was 20.0 °C: the previous hottest summer, again by mean daily temperature, was just last year (2025) at 18.7 °C, while summer 1976 averaged 18.5 °C.

 

May, June and July were all the hottest months of that name in almost 120 years records, and unprecedented run of extreme months. Despite a much cooler final week, August was the equal second-hottest on record, just one tenth of a degree below 1995.

 

Summer 2026's mean daily maximum temperature was 26.2 °C; the previous highest such figure was in summer 1976, at 24.7 °C. In addition, new monthly records for Reading's hottest days on almost 120 years of record were set this year in May (33.0 °C on 25 and 26th), June (34.9 °C on 24th) and August (36.7 °C on 13th). The maximum temperature on 13 August was the second-hottest day ever recorded in Reading.

 

Maximum temperatures reached or exceeded 30 °C on 18 days during June-July-August, plus another three such days in May, making 21 for the year to date. The greatest number of days reaching 30 °C in any previous year was 14, in 1976. This year's total is also greater than the decadal total for the whole of the 1950s (12), 1960s (just 5), 1970s (17, including 1976's 14), 1980s (18) and 1990s (16), and is clear evidence of our warming climate. The last 10 years, including 2026 to date, have produced 77 such days.

 

The threshold for 'heatwave' conditions vary across the country; in Berkshire, it is three or more consecutive days at or above 28 °C. This year we have had five such heatwaves by that definition up to the end of August: 23-28 May (6 days), 21-27 June (7 days), 5-13 July (9 days), 15-17 July (3 days), and 12-14 August (3 days). In all, 28 days were part of 'heatwave' spells. (But for one day, 14 July, failing to reach the threshold with a maximum temperature of 27.7 °C, we would have recorded four heatwaves across 29 days, the longest would then have been 13 days, 5-17 July.) The only previous year in Reading to see five heatwaves by the modern definition was in 1911, but the spells that year were shorter (none longer than 3 days), while the total days involved (15) was barely half of this year's count. Summer 1995 saw 20 such heatwave days, across four spells.

 

Night temperatures were also at record levels. The mean daily minimum temperature for summer 2026 was 13.8 °C: the previous highest mean minimum temperature for any previous summer since 1908 was 13.2 °C, in 2003. New records were set for the hottest night in May (17.4 °C on 27th) and in any month of the year (21.3 °C, on 26 June). The 25th and 26th June were Reading's warmest and second warmest nights in the entire near 120 year record.

Rain fell on 23 days in all during summer 2026, mainly at the beginning and end - summer 1996 received rain on only 13 days, and 1976 on 14. However, in the 64 days from 15 June, measurable rainfall fell on just four days, amounting to just 2.5 mm. A normal year would produce over 100 mm of rainfall during that period.

 

July was the driest on the university's long records, while some parts of the Reading area received no measurable rainfall at all during the month: the first and only time this has happened in a calendar month since the earliest continuous rainfall records for the Reading area began in 1858. Rainfall in the first half of June and the last week of August was enough to push summer 2026 just out of the 'Top 10' driest summers on the university's records. 

Following a notably gloomy winter, every month since and including March has been sunnier than normal; so sunny that in fact we surpassed the average annual duration of sunshine on 25 August. Every hour of sunshine from now to New Year's Eve is therefore a bonus!

 

July, with 364 hours of sunshine, a remarkable average just shy of 12 hours per day, was by far the sunniest month ever recorded in Reading, surpassing May 2020's previous record of 345 hours. Summer 2026 saw 891 hours of sunshine in all, a remarkable daily average of 9.7 hours. Summer 2026 surpassed summer 1976's total of 843 hours on 24 August.

 

The total sunshine duration for spring and summer combined, March to August, stands at 1508 hours to date, and is already by far the highest spring+summer total on record (sunshine records began at the university 70 years ago): the previous sunniest such period was in 2020, with 1389 hours recorded.