Monthly Outlook

The weather will stay changeable through until mid-September, with occasional heavy rain, thunderstorms and rather strong winds possible.

Later in September high pressure may build and bring a drier period with above-average temperatures before unsettled conditions potentially return by early October.

Changeable. Possibly drier and cooler later

Saturday will be bright and breezy, with mostly dry conditions in southern and eastern regions but some showers in the northern and western UK. They will be potentially heavy and thundery in western Scotland.

Winds will ease later as a high pressure ridge crosses, but that will continue to pass eastwards to allow a rain-bearing frontal system to move across Northern Ireland and Scotland on Sunday and Monday, with stronger winds. Most of the UK will be dry and warmer, however, at least on Sunday. A front will weaken as it moves south-eastwards Monday, just producing a few scattered showers.

The rest of the coming week should have occasional Atlantic weather systems passing through, bringing further periods of rain, some perhaps thundery, with brighter and drier but potentially showery interludes. Temperatures are most likely to be near to a little above normal, with southern England in particular feeling warm in the sunnier spells.

At the weekend there may be a change. High pressure could start to build to the west of the UK, which may cause winds to come from a slightly cooler north-west to north-easterly direction. This could also start to deliver drier conditions to some areas right at the end of the week but that process could be delayed.

Turning drier and warmer

After mid-September, there are signs that high pressure could expand and build across the UK, leading to longer drier and calmer periods. Rainfall amounts should be below normal widely for the week, although conditions are unlikely to be completely dry. The main low pressure track and frontal zone should be pushed north-wards, with parts of Scotland likely to have the highest chance of seeing some closer-to-seasonal amounts of rain.

Temperatures should increase, with above-average warmth most likely overall, although the climate average is gradually dropping now.

With the nights getting longer, some cool mornings are possible under clear and calm conditions, and patches of mist and fog are possible as well.

Most likely drier and warmer than average

A further boost to the temperature may come later in September, between the 21st and 27th, if high pressure shifts to the south and east, and draws in more of a south-east to southerly flow.

Either way, above-average temperatures are more likely than below, and it should stay drier than normal in most areas, although eastern coasts may be cloudier and seasonably cooler under these circumstances.

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 a low chance that high pressure will be centred more to the west or north-west, which might mean a slightly cooler but still fairly dry period

On Tuesday we will see if models and climate signals still point towards drier conditions after mid-September, and if there are signs of more unsettled weather developing by early October.