The month ahead

The monthly outlook is based on output from global forecasting models and our own analysis.

September weather: Mixed, wettest mid month

Forecast issued 31/08/2021


Slightly above average.


Close to average.

1/9 to 7/9

Dry start then more unsettled.

The first few days will be dry in much of the UK, but in the east thicker cloud brings some drizzle or light rain. There will be bright spells too, with the best of them in the west and north west. Cool in overcast areas, but feeling warm in sunny spells. Through the second half of the week a transition to more changeable weather takes place. The risk of showers or longer spells of rain increases and it could become quite windy. It may remain drier in Scotland.

8/9 to 14/9

Changeable. [Forecast confidence is low]

Mixed weather is forecast to bring showers which could be thundery in southern and central regions. Longer spells of rain are possible too, particularly to the north west of the UK. However, the south and east probably have a good deal of dry weather with sunny spells and variable amounts of cloud. Temperatures close to the average in the north west, but above it elsewhere. Possibly very warm for a time in the south and south east. 

[Note: The is a lot of uncertainty about the influence of high pressure through this week.]

15/9 to 30/9

Becoming more settled. [Forecast confidence is low]

Computer models are suggesting quite unsettled weather early in the second half of the month. That leads to the likelihood of wet and windy spells, particularly in the west and north west. During the last third of the month there is a signal for it to turn drier and more settled, particularly in the south and west. Over the period as a whole temperatures are expected to be slightly above average in the south and close to average in the north. 

Accompanying video



Important note about long range weather forecasts: It is considered impossible to say with certainty what the weather will be like more than a few days ahead in the UK. Long range forecasts on TheWeatherOutlook have not been independently verified, and we make no claims for their accuracy. A range of factors including seasonal computer models, recent weather patterns, sea surface temperatures and teleconnections are considered when making the forecasts.


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