Monthly Outlook

After further changeable conditions high pressure should become more evident by mid-September and bring longer periods of drier weather with above-average temperatures.

Unsettled conditions could potentially start to return through early October.

Changeable. Cooler for a couple of days

Wednesday should become drier but a little cooler as a ridge of high pressure crosses the UK. Temperatures will be closer to average, with just a few showers dotted around and some sunshine in most areas. However, throughout Thursday and Thursday night, a frontal system will gradually bring a band of rain from the west as high pressure topples away eastwards, with brisk and gusty winds developing along with a slight chance of a thunderstorm.

The remainder of this week should have a similarly changeable pattern, with another transitory high pressure ridge bringing drier weather during Friday. There should be further sunny periods with only isolated hit and miss showers.

The next frontal system at the weekend will probably deliver the wettest and windiest weather to the northern and north-western UK, with some sharp showers following.

High pressure could build more strongly across the south of the UK, causing the frontal rain to weaken and fragment before it reaches the south-east. Away from the rain, there should be a warmer trend, with temperatures rising above normal.

Turning drier later in the week

A similar pattern may continue into at least the first half of next week, with further struggles between Atlantic frontal systems and high pressure trying to build from the south and south-west.

For a few days there could be further bands of rain sweeping across from the west, with the north and west of the UK seeing the wettest and windiest weather along with some isolated thunderstorm risks, while the south and east have a higher chance of longer drier spells. In between, transient high pressure ridges should deliver temporary drier weather. Temperatures should be around the seasonal average in northern regions, and above in the south.

After midweek there are signs that high pressure could expand more across the UK, leading to longer drier and calmer periods for many areas. Rainfall amounts should be below normal widely for the week, with the main low pressure track and frontal zone pushed farther northwards. That should mean that parts of Scotland are likely to have the highest chance of seeing more seasonal amounts of rain.

For most areas temperatures should be above normal, although of course the climate average is gradually falling now. With the nights getting longer some relatively cool mornings are possible under clear and calm conditions, and patches of mist and fog are possible by the end of the week as well.

Most likely to be drier and warmer than average

Although high pressure is most likely to stay nearby later in September, it may become centred slightly to the west of the UK. This might allow one or two frontal systems to bring more seasonable rainfall amounts, at least to some northern parts of the UK, but significantly wet weather is not expected, and southern regions may stay relatively dry. This might also bring winds from a slightly cooler direction, with more seasonal temperature values possible in northern areas, although probably still above normal in the south.

A renewed temperature boost may come by early October if indications of high pressure shifting to the east are eventually realised. This could draw in more of a south-east to south-westerly flow, with higher chances of above-average temperatures. It should stay drier than normal in most areas.

If high pressure moves far enough away, then it might eventually allow low pressure systems to approach the UK from the west or south, leading to increasing chances of rainfall and potentially thunderstorms. There is also a low chance that high pressure will be centred more to the west or northwest, which might mean a slightly cooler but still fairly dry period.

On Friday models and climate signals may still point towards drier conditions by later September, but with the outlook extending farther into October there may be signs of unsettled weather eventually returning.