Tuesday is set to bring late September warmth to parts of the UK, with temperatures potentially topping 26C in some spots. The warmest readings will show up in the south-east of England, while much of the rest of the country should see temperatures get well into the 20s Celsius across England, with the high teens Celsius elsewhere.
The temperatures will sit roughly 3 to 7 degrees above what’s typical for the season. Overnight into Tuesday morning, the warmth will persist, with some spots barely dipping below 20C.
What Is Bringing The Heat
A rise in temperatures is expected as a powerful flow of air from the south strengthens through Tuesday. Hot air from France and Spain, where readings have regularly passed 30C, will be carried into the UK by the wind.
A strong low pressure system over the eastern Atlantic, heading toward Iceland, is bringing stronger southerly winds. Gusts up to 50mph are expected across Northern Ireland and western Scotland.
Where The Warmth Lands
England’s thermometer readings will top 20C in many places. The warmest air masses will settle over south-east England, pushing temperatures into the mid-20s Celsius there.
England’s average late September temperatures sit around 16 to 19C. The warmest spots will fall across the south-east of the country, while temperatures will generally reach the 20s Celsius across England and the high teens elsewhere.
Tuesday will see above-average warmth across Wales, Northern Ireland and Scotland, with maximum temperatures reaching 17 to 22C. The day will begin sunny, though cloud cover is expected to build up as the afternoon progresses.
The Night Will Not Cool Down
Overnight into Wednesday, the warm southerly winds persist, and minimum temperatures will feel more like a summer night than what early autumn usually brings.
Across much of the region, temperatures will stay between 15 and 19 degrees Celsius. In some areas of south-east England, overnight lows could remain above 20 degrees Celsius.
This is a notably warm night for late September, with overnight temperatures usually falling to around 7 to 11C.
A Warmer Than Average Month
September will mark another month where average temperatures will come in well above normal. Up to 26 September, the Central England Temperature (CET) — the world’s longest continuous instrumental temperature record, which tracks the average temperature across various locations in England — is 2.6 degrees Celsius above normal.
This year, every month has come in with an average mean CET above what is typical. The year to date stands at a temperature that is 2.6C above the norm.
For 2026 to avoid being among the warmest years on record for the UK, temperatures across the remainder of the year would have to be far below average.
The Met Office has released its most recent three-month outlook, covering October through December, and it points to above-average odds for a mild autumn and early winter.
What To Expect On Tuesday
Tuesday morning may bring some cloud along with a few showers, though sunny spells will break through over England and Wales. Temperatures will rise above normal across Wales, Northern Ireland and Scotland.
England and Wales will start the day with sunshine, but the cloud will grow throughout the morning and afternoon.
Hard Numbers
- Peak temperature: 26C in parts of south-east England
- Average for the time of year: 3 to 7 degrees below the current forecast
- Nighttime minimum: 15 to 19C widely, potentially staying above 20C in south-east England
- Central England Temperature (CET) through 26 September: 2.6 degrees Celsius above normal
- Year-to-date CET anomaly: 2.6C above normal
- Met Office outlook: Higher-than-normal chances of a mild autumn and start to winter
The warmth is coming from the south, and the air feels unusually hot, giving the UK an early taste of what the season usually offers. Whether this particular stretch of warmth ends up being remembered as a notable event will depend on how the rest of the year plays out. For now, the message is straightforward: make the most of the sun while it remains.
Source material: “Temperatures to hit 26C in burst of late September warmth,” the BBC.
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