UK temperatures could climb to 26C in parts of southern England on Tuesday as a burst of late September warmth pushes readings well above the seasonal average.
The highest temperatures are expected in south-east England, while much of England will see temperatures reach the low or mid-20s Celsius. Elsewhere, Wales, Northern Ireland and Scotland will also experience warmer-than-average conditions, with temperatures reaching the high teens or low 20s.
UK Temperatures Rise Above September Average
The UK temperatures will be around 3 to 7C higher than the average for late September in many areas. Average temperatures across England at this point of the month are generally between 16C and 19C.
The rise in temperatures is being driven by a strong southerly airflow developing on Tuesday. Warm air from France and Spain, where temperatures have widely exceeded 30C, will be carried north towards the UK.
South-east England is expected to experience the highest UK temperatures, with readings reaching the mid-20s Celsius. Temperatures above 20C will be widespread across England as the warmer air moves across the country.
Cloud and a few showers could affect parts of the country on Tuesday morning, but sunny spells are expected to develop across England and Wales during the day. Wales, Northern Ireland and Scotland will also be warmer than normal, with maximum temperatures between 17C and 22C.
26C UK Weather Brings Unusually Warm Night
The unusual warmth will continue after sunset, with Tuesday night expected to remain significantly milder than normal for late September. Temperatures will generally stay between 15C and 19C overnight.
In parts of south-east England, temperatures may not fall below 20C, producing a night that is more typical of summer than early autumn. Normal overnight temperatures in late September are around 7C to 11C.
Strong southerly winds will also remain a feature, particularly across Northern Ireland and western Scotland. Gusts of up to 50mph are expected in those areas as a large and deep area of low pressure moves northwards across the eastern Atlantic towards Iceland.
Late September Warmth Extends a Warmer 2026
The latest spell of late September warmth comes as the month is on course to be another warmer-than-average period in the UK. Up to 26 September, the Central England Temperature record was 2.6C above normal.
The Central England Temperature record is the world’s longest-running temperature record and tracks average temperatures across various locations in England. Every month of 2026 so far has recorded an average mean CET above normal.
The year-to-date CET is also 2.6C above average. According to the source, temperatures would need to be much colder than normal during the remaining months for 2026 not to rank among the UK’s warmest years on record.
The Met Office’s latest three-month outlook, covering October to December, also indicates higher-than-normal chances of a mild autumn and a mild start to winter.