BBC monthly outlook
Monday 5 September—Sunday 11 September
Summer warmth to return - for a while
The first Monday in September will see mostly cloudy skies across the country, although eastern counties will be mostly dry and may start bright. Occasional rain further west will turn light and patchy, with a lot of hill fog developing in the west. On Tuesday, much of Scotland will have sunny spells but other areas will start cloudy and misty. It will brighten up in places, and it will feel warm and humid where this happens. The warming trend continues on Wednesday and Thursday, with increasing amounts of sunshine. Temperatures may reach 28 Celsius in the east. Scotland and Northern Ireland retain the risk of some showers. Late in the week, stronger winds from the Atlantic will bring a drop in temperatures and also bands of rain or showers which will chiefly affect the northwest.
Monday 12 September—Sunday 18 September
Often dry and warm in the southeast
Heading towards mid-month, the week's weather pattern is expected to feature high pressure close to southeast England or over the near continent. This will bring a lot of fine weather to much of England and Wales, with daytime temperatures on the warm side. Scotland and Northern Ireland will be under a run of sometimes strong south-westerly winds from the Atlantic: these northwestern parts will also have some fine periods but also some showers and perhaps one or two longer outbreaks of rain. These will weaken as they head south-eastwards into England and Wales, bringing only brief interruptions to the dry weather.
Monday 19 September—Sunday 2 October
Settled weather expected to dominate
For late September, current indications are for northwestern parts to continue rather unsettled for a while, with occasional bands of wet and windy weather. Meanwhile, all southern and eastern areas will have lengthy periods of dry weather, with above average temperatures, and only short periods of cloud and the threat of rain. Late in the month, some more settled spells may also affect northern parts. As always, the forecast for this far ahead is never certain, and as the northern latitudes begin to cool down more quickly at this time of year there is always the chance of sudden changes in the weather pattern.
Next week
Next week's outlook will take a fresh look at how early autumn is shaping up. Will the benign southwesterly winds continue? Or can we expect the first autumnal gales?
http://www.bbc.co.uk/weather/2635167#outlook