The United Kingdom experienced its joint-fourth warmest September on record, according to provisional data released by the Met Office. The highest temperature reached during the month was 28.1 degrees Celsius on September 29, matching figures recorded in 1949 and 2016.

Mike Kendon, a climate information scientist at the Met Office, noted that "persistent warmth has been the theme of recent months," with September continuing this trend. High pressure systems were especially dominant across southern parts of the UK during the latter part of the month, contributing to the elevated temperatures.

Despite the relatively warm start to the autumn season, meteorologists have forecast a shift towards cooler and more unsettled weather as the year progresses. This change is expected to be influenced by the El Niño weather phenomenon, which occurs when sea-surface temperatures in the central and eastern Pacific Ocean rise significantly above average. El Niño is known to affect weather patterns worldwide, potentially bringing cooler conditions to the UK later in the year.