Parts of the UK are expected to experience a burst of late September warmth on Tuesday, with temperatures potentially reaching 25C. The warmest conditions are forecast for south-east England, though temperatures across England are widely expected to be in the 20s Celsius, and in the high teens elsewhere.
These temperatures will be approximately 3 to 6 degrees above the seasonal average. A strong southerly airflow, bringing warm air from France and Spain, is contributing to the rise in temperatures.
Tuesday night is also predicted to be unusually warm. In some locations, particularly in south-east England, temperatures may not fall much below 20C. This is significantly higher than the typical late September overnight temperatures of 7 to 11C.
September 2026 is on track to be another warmer-than-average month. Up to September 26, the Central England Temperature (CET) was 2.6 degrees Celsius above normal. Every month this calendar year has recorded an average mean CET above average.