Unprecedented Warmth in September for the UK
September 2026 has been recorded as the joint-fourth warmest September in the United Kingdom since records began in 1884, according to preliminary data. The month was notably characterised by a late surge in temperatures, with a peak of 28.1°C reached on the 29th of September. The overall mean temperature for the month stands at a provisional 14.6°C, aligning it with the warmest Septembers recorded in 1949 and 2016.
While rainfall levels throughout the month were generally in line with historical averages, significant regional disparities were evident, particularly in southern and eastern England, which experienced notably dry conditions.
Continuing the Trend of Above-Average Temperatures
The warm spell follows what has been provisionally termed the hottest summer on record, with September maintaining the pattern of elevated average temperatures observed throughout much of 2026. Mike Kendon, a Climate Information Scientist at the Met Office, noted that the persistent warmth has been a consistent theme, with September 2026 matching historical temperature highs due to the influence of high-pressure systems, particularly in southern regions as the month progressed.
Kendon pointed out that while the month may have appeared unremarkable in isolation, it fits into the broader context of a warmer year, reflecting a trend of increasing temperatures in the UK as climate change continues to manifest.
Regional Variations in Temperature Records
The warmth of September was not experienced uniformly across the UK. Wales marked its joint-sixth warmest September, while England reported its third warmest and Northern Ireland its fourth. Scotland, although warmer than average, just missed the top ten warmest months on record.
Overnight temperatures also recorded significant highs, with the UK achieving its joint-fourth highest average minimum for the month. Northern Ireland experienced its highest average minimum, while Scotland, England, and Wales ranked fifth, fourth, and fourth, respectively.
Rainfall Patterns and Drought Concerns
Despite near-average rainfall across the UK, significant regional differences were observed. Scotland recorded over a third more rainfall than its typical monthly average, whereas southern England remained relatively parched, even following some recent precipitation. Philip Duffy, Chief Executive of the Environment Agency, highlighted that while the rainfall in September was a welcome development, it is insufficient to rectify the water shortages stemming from a dry spring and an exceptionally hot summer.
Duffy emphasised that true recovery from drought conditions will only be achieved once groundwater, rivers, and reservoirs return to normal levels, a process that will require months of consistent wet weather. He urged continued water conservation efforts to support local ecosystems, farmers, and wildlife.
Sunshine Levels Across the UK
Sunshine hours for September were generally around the average for the UK; however, Northern Ireland recorded significantly less sunshine than usual, though it did not set any records for dullness.
Summary of September 2026 Statistics
The provisional statistics for September 2026 reveal the following:
Mean Temperature (°C): UK: 14.6 (anomaly: +1.6), England: 16.0 (+2.0), Wales: 14.6 (+1.6), Scotland: 12.3 (+1.0), Northern Ireland: 14.0 (+1.5)
Rainfall (mm/% of average): UK: 94.7 (104%), England: 44.8 (65%), Wales: 112.5 (101%), Scotland: 169.0 (137%), Northern Ireland: 118.4 (135%)
Sunshine (hours/% of average): UK: 124.6 (98%), England: 142.7 (101%), Wales: 114.8 (89%), Scotland: 102.7 (96%), Northern Ireland: 92.0 (81%)
Understanding Monthly Data Sources
The monthly climate statistics utilised by the Met Office are based on HadUK-Grid data, which calculates averages for counties, regions, and the UK as a whole. This dataset compiles weather observations from across the nation and interpolates them onto a 1km x 1km grid, ensuring comprehensive coverage of the UK. Some records date back to 1836, providing nearly two centuries of weather data.