Met Office September heatwave forecast: UK could face more hot weather into September
Record UK heatwave linked to thousands of deaths in 2026. Image Credit: Aaron Chown/Press Assn
Britain’s record-breaking summer could continue into September, with the Met Office warning that above-average temperatures and further spells of hot weather remain possible as summer draws to a close.
The latest Met Office long-range forecast says high pressure could dominate the UK from late August into early September, creating periods of drier-than-average weather. Temperatures are expected to be above average, while hot weather and heatwaves remain possible, particularly in southern England.
The outlook comes as the UK faces another spell of extreme heat, with an amber warning covering large parts of England on Thursday, August 13. Temperatures could reach around 37C to 38C, adding to a summer that has already produced multiple heatwaves and notable temperature records.
Met Office September Forecast Signals More Hot Weather
The Met Office’s latest long-range forecast covers the period from Thursday, August 27 to Thursday, September 10. It says high pressure will probably be dominant near the UK during this period, bringing periods of dry weather to many areas.
Rain is still possible, particularly during more unsettled interludes, but overall rainfall is currently considered more likely to be below average than above average.
The temperature signal is particularly notable. The Met Office expects temperatures to be above average, with some spells of hot weather and heatwaves possible, especially across southern parts of the country.
That does not mean a September heatwave is guaranteed. The agency stresses that long-range forecasts indicate broad weather patterns rather than predicting exactly when or where a heatwave will occur.
Could the UK Have a September Heatwave?
Yes, another UK heatwave in September is possible, according to the latest Met Office outlook, but there is not yet enough certainty to predict a specific heatwave event.
The current forecast points towards an increased chance of hot conditions during the late-August and early-September period. Southern England appears to have the strongest signal for warmer weather.
The Met Office previously warned that the risk of further heatwaves would increase as August progressed. Its July outlook said temperatures were expected to remain above average overall, while further heatwaves later in the summer were possible.
The latest forecast suggests that this warmer pattern could potentially extend into the opening days of September.
Why September Could Still Be Hot
The key factor behind the forecast is high pressure.
When high pressure becomes established near the UK, it can encourage clearer skies, longer periods of sunshine and reduced rainfall. If warm air is also drawn towards Britain, temperatures can climb significantly.
The current Met Office outlook suggests high pressure could remain influential between late August and early September, creating conditions favourable for dry, warm and potentially hot weather.
However, high pressure does not guarantee continuous sunshine everywhere. Atlantic weather systems can still move into parts of the country, while thunderstorms and showers may develop, particularly in warmer southern areas.
Southern England Faces Greater Heatwave Risk
The south of England is currently the part of the UK with the clearest signal for potential hot weather during the late-August and early-September period.
The Met Office specifically says some spells of hot weather and heatwaves are possible, especially in the south.
This could mean southern areas experience higher temperatures while northern parts of the UK see more cloud, rain or cooler conditions during interruptions to the high-pressure pattern.
The regional picture will become clearer as September approaches, with shorter-range forecasts expected to provide more reliable information.
UK Faces Another Extreme Heat Spell in August
The September forecast comes as the UK is already experiencing another major burst of summer heat.
On Thursday, August 13, the Met Office extended an amber Extreme Heat Warning to cover additional parts of England. Temperatures were forecast to reach around 37C, with the possibility of locally higher readings.
The current heatwave has also produced very warm nights. Parts of southern England experienced what the Met Office describes as a tropical night, when temperatures remain at or above 20C throughout the night.
Such conditions can make it difficult for people to sleep and recover from daytime heat. The Met Office says prolonged high overnight temperatures can increase cardiovascular stress and contribute to sleep disruption.
2026 Could Become the UK’s Hottest Summer on Record
The unusually hot conditions are part of a much bigger weather story.
The Met Office has said the summer of 2026 is on course to become the UK’s hottest summer since records began in 1884, following record-breaking warmth during earlier months.
The UK has already experienced notable heat records during 2026, while the latest August heatwave is adding further extreme temperatures to the seasonal total.
The Met Office’s broader three-month outlook for July to September 2026 had already indicated that the chance of a hot three-month period was higher than normal, bringing an increased risk of further heatwaves and heat-related impacts.
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What Will September Temperatures Be?
It is too early to give a reliable day-by-day temperature forecast for September.
The average UK temperature for September is around 17C, but the latest longer-range outlook suggests temperatures are likely to be above average during the period from late August into early September.
That means some days could be considerably warmer than the seasonal average, particularly in southern England, but the Met Office has not issued a specific forecast saying that temperatures will reach a particular number throughout September.
Forecast confidence increases as the date gets closer.
Met Office Warns Long-Range Forecasts Can Change
People planning holidays, outdoor events or travel should be cautious about treating the September heatwave forecast as a certainty.
The Met Office explains that forecasts beyond five days become increasingly affected by the chaotic nature of the atmosphere. Small changes in weather systems can produce significant differences in UK conditions several days later.
The agency therefore uses longer-range forecasts to describe the general direction of weather patterns, rather than promising specific temperatures for individual towns or dates.
The September outlook is likely to change as new forecasting data becomes available.
What Happens to the UK Weather After the August Heatwave?
The current August heatwave is expected to ease, with temperatures gradually falling after the peak of the hot spell.
Sky News meteorologist Kirsty McCabe said temperatures could reach around 38C before falling towards the mid-30s and then the high 20s as fresher air moves in from the northwest.
That does not necessarily signal the end of hot weather for the summer. The Met Office’s latest long-range forecast leaves open the possibility of another warm or hot spell as August ends and September begins.
What Should People Expect in September?
The most likely message at this stage is changeable but potentially warmer-than-average weather.
There could be lengthy dry periods under high pressure, interrupted by showers, rain or thunderstorms. Southern areas have a greater chance of experiencing hot spells, while other parts of the UK could see more mixed conditions.
The Met Office will continue updating its forecast as September approaches.
For now, the prospect of another September heatwave in the UK is possible but not certain. The strongest signal is for above-average temperatures and periods of dry weather rather than a guaranteed prolonged heatwave.
FAQ
Will there be a heatwave in the UK in September 2026?
A September heatwave is possible but not guaranteed. The Met Office’s current long-range forecast says temperatures are likely to be above average from late August into early September, with some spells of hot weather and heatwaves possible, particularly in southern England.
What is the Met Office September 2026 forecast?
The latest Met Office forecast for August 27 to September 10 indicates that high pressure will probably dominate near the UK for periods, producing generally dry conditions. Temperatures are expected to be above average, with the possibility of hot weather and heatwaves, especially in the south.
Will September 2026 be hotter than normal?
The current outlook suggests above-average temperatures are more likely during the late-August and early-September period. However, this does not mean every day will be hot or that September as a whole will set a temperature record.
Where in the UK could be hottest in September?
The Met Office currently identifies southern parts of the UK, particularly southern England, as having a greater possibility of hot spells and heatwave conditions.
Could another UK heatwave happen after the August heatwave?
Yes. The current August heatwave is not necessarily the last hot spell of 2026. The Met Office says further heatwaves are possible later in the summer, while its current long-range forecast also leaves open the possibility of hot weather into early September.
How hot will the UK be in September 2026?
There is no reliable day-by-day September temperature forecast yet. The Met Office currently says temperatures are likely to be above average, but exact temperatures will become clearer closer to September.
What is the average UK temperature in September?
The average UK temperature in September is around 17C, according to the forecast information reported from the Met Office’s longer-range outlook. Actual temperatures vary considerably between regions and individual days.
Will September be dry in the UK?
The current outlook suggests periods of dry weather for many regions, with overall rainfall more likely to be below average than above average during August 27 to September 10. Some unsettled periods with showers or longer spells of rain are still possible.
Why is high pressure important for the September forecast?
High pressure is often associated with more settled and drier weather. If it remains established near the UK while warm air moves into the country, it can create conditions favourable for high temperatures and heatwaves.
Is the September heatwave forecast certain?
No. It is a long-range forecast, not a confirmed prediction of a specific heatwave. The Met Office says forecasts beyond five days have greater uncertainty because relatively small changes in atmospheric conditions can significantly affect the UK’s weather.
When will the Met Office September forecast become more accurate?
Forecast confidence generally improves as the date approaches. Shorter-range forecasts provide more detail about individual regions, temperatures, rainfall and potential weather warnings.
Could the September heatwave affect southern England more?
The current Met Office outlook suggests southern England has a greater chance of hot spells and heatwaves during the late-August to early-September period. Regional conditions can change as the forecast is updated.
Is the UK still experiencing a heatwave in August 2026?
Yes. On August 13, 2026, the Met Office had an amber Extreme Heat Warning covering large parts of England, with temperatures expected to reach the upper 30s Celsius in some locations. The current spell is part of an unusually hot summer.
Could September 2026 bring another 30C day?
It is possible, particularly in southern England, but the Met Office has not yet issued a specific 30C forecast for September. The current outlook only establishes an increased possibility of above-average temperatures and hot spells.
Will September be cooler than August?
September is normally cooler than August because the season is transitioning towards autumn. Even so, the Met Office’s current outlook indicates that temperatures could remain above average during the opening part of September.
Could the UK have a September heatwave after a cooler spell?
Yes. UK weather can shift rapidly between cooler, wetter conditions and warmer settled spells. A temporary drop in temperatures during August would not rule out another hot spell later.
Why has the Met Office mentioned more heatwaves in 2026?
The Met Office’s three-month outlook for July to September indicated that the chance of a hot three-month period was higher than normal, with an increased risk of further heatwaves and heat-related impacts.
Is 2026 on track to be the UK’s hottest summer?
The Met Office has said the summer is on course to be the UK’s hottest since records began in 1884, following exceptional warmth during the year. The final assessment will depend on temperatures recorded across the remainder of the season.
Should people change September travel plans because of the forecast?
There is not enough certainty to make major travel decisions based solely on the current long-range forecast. Anyone travelling in September should check the Met Office’s latest regional forecast closer to their travel date.
Where can I check the latest Met Office September weather forecast?
The Met Office updates its long-range forecast regularly and provides increasingly detailed information as the forecast period gets closer. The official forecast is the best source for current UK weather warnings and regional conditions.