The Met Office Forecast for September: What It Actually Says

The Met Office’s forecast for September 2026 runs out on the 14th.

When we read its long-range page, it carried exactly two blocks: one for 21 to 30 August, and one for 31 August to 14 September. For the second half of September there was nothing — not a hedge, not a probability, nothing at all.

For the half it does cover, the summary is undramatic: signals are weak, near-normal is most likely, temperatures are likely to be above average, and there is a chance of late hot spells in the south.

What does the Met Office actually say about September?

Here is the whole thing, verbatim. This is the block headed “Monday 31 Aug - Monday 14 Sep”, as we retrieved it at 17:08 GMT on 16 August 2026:

“As we move into the start of meteorological autumn, signals for the prevailing weather patterns affecting the UK are weak, thus something close to the climatological norm is most likely. This means a broad northwest-southeast split in conditions, with the high pressure becoming centred close to the south of the UK and more changeable conditions developing towards the north and northwest. Meanwhile, drier, more settled weather is slightly more likely towards the south and east. Temperatures are likely to be above average overall. There is a chance that late season hot spells or heatwaves develop, especially in the south.”

Read the hedges, because they are the content. “Signals … are weak”. “Most likely”. “Slightly more likely”. “A chance that … hot spells or heatwaves develop”. This is a forecast written by people who are telling you how much they do not know.

Why does it stop on 14 September?

Because that is where the product ends. The long-range forecast looks out about 30 days from the day you read it, and it is rewritten daily. On 16 August, 30 days out was mid-September.

The Met Office is candid about why it will not go further, and about why even the part it does publish is written for the whole country rather than your town:

“when looking at forecasts beyond five days into the future the chaotic nature of the atmosphere starts to come into play … whilst we can still forecast the general feel of the weather to a relatively high level of accuracy using our ensemble models, it becomes harder to offer local detail”

So what about the second half of September?

Nothing has been published, and that is the honest answer.

We should be precise about the limits of that statement. It means we found no Met Office forecast covering 15–30 September, and none from the other forecasters we could reach. Several UK news sites refused our requests outright, and one long-range specialist blocked us site-wide — including its own homepage, which voids the test rather than proving absence. So: no Met Office forecast, and none that we could find elsewhere.

What this does mean is that any article you see today giving a temperature, a date or an “exact day” for late September has no published forecast behind it. It is either a single model run — which changes every six hours and is not a forecast — or it is invention.

Does the three-month outlook say more?

It says something, but it is not a September forecast, and it is easy to misread in two separate ways.

The Met Office publishes a 3-month Outlook for contingency planners. The current one covers August to October 2026 as a three-month average, and its single-month section is for August. September is the middle month of the window, but there is no September-specific section in it. That arrives on 1 September, when the September–November issue is published.

Normal is 20% for each outer band and 60% for near average, so:

The first trap: these are not thirds. The Met Office’s own normal likelihoods are 20 / 60 / 20, not 33 / 33 / 33. If you assume thirds, 45% looks like a mild 1.35×. Against the real baseline it is the 2.3× the Met Office prints — nearly double the apparent signal.

The second trap: the heat is front-loaded. The outlook’s summary places the increased heatwave risk “especially during the first half of the period” — that is August and early September — and says the chance of rain and wind impacts becomes “slightly higher than normal later in the period”, which points towards October. Read as a September document, it says less than it appears to.

“Close to the climatological norm” — what is normal?

A normal UK September is 12.93°C, with 90.9mm of rain and 127.5 hours of sunshine, on the 1991–2020 baseline.

The forecast’s other structural claim is a “broad northwest-southeast split”. That phrase sounds like a forecast of something unusual. It is not — it is a description of what September in the UK is like every year.

Scotland’s average September is 1.8 times wetter than England’s and gets about a quarter less sunshine. So when the Met Office says both “close to the climatological norm” and “a northwest-southeast split”, it is not saying two things. It is saying the same thing twice.

“Above average” — above which average?

This is where a real number can mislead without anyone lying. The 1991–2020 UK September mean is 12.93°C. The 1961–1990 mean is 12.20°C. The most recent thirty years, 1996–2025, average 13.22°C.

A September that comes in at 13.0°C is “above average” against two of those three and below the third. When you read “above average”, the useful question is not how much — it is against what.

For context on the range: the warmest UK Septembers on record are 2006 and 2023, tied at 15.2°C, and the coldest is 1952 at 9.9°C. Five of the ten warmest have occurred since 2000.

Does any of this mean another heatwave?

The Met Office has not forecast one. The strongest language it uses is “a chance that late season hot spells or heatwaves develop, especially in the south” — and its three-month outlook states in terms that it does not guarantee heatwaves.

That is worth holding onto given the summer behind it. As we covered when the August heatwave broke , 2026 had already produced six heatwaves and records at several thresholds before September began. A warm September would not be surprising. But “would not be surprising” is not a forecast, and the Met Office has not issued one.

What about the drought?

The forecast will not answer that question, and this is the part that actually affects people.

By mid-August, all of Wales and around half of England were in official drought status, with hosepipe restrictions covering millions of households. Those restrictions come off on the state of reservoirs and rivers, not on a weather outlook — and a “drier, more settled” first half of September in the south and east, which is what the Met Office describes, is the opposite of what would lift them.

If you want to know whether a ban applies to you, your water company’s own page is the authority. We keep a guide to the 2026 hosepipe bans and the areas they cover .

What to check, and when

• For the next week, use the location forecast, not the long-range page. The long-range text is written for the UK as a whole by design and will never mention your town.
• Check the long-range page once a day at most, and read the date headings before the words — both the wording and the period boundaries move daily.
• Put 1 September in the diary. That is when the Met Office issues its September–November outlook, the first product with a September-specific section.
• Treat anything about 15–30 September as noise for now. No published forecast covers it.
• When you see “above average”, check the baseline. Against 1961–1990 it means something different from against 1991–2020.
• Warnings only run seven days out. There is no such thing as a September weather warning today.

Sources

Checked 16 August 2026. No affiliate links, and no payment was received for any link on this page.