Updated 18th August - Covering 25th Aug - 16th Sept 2025
Mean temperatures, relative to the 1991-2020 long-term normal, are expected to be about 1C above average in most eastern parts of the UK, perhaps up to 1.5C above in parts of eastern England, but nearer normal in the west.
Rainfall totals are forecast to be above normal for most of the country, but perhaps near normal for parts of northern, especially north-western, Scotland, and parts of eastern and southern England could end up with near average rainfall despite wet weather in Week 2.
Sunshine totals will probably be near normal in most eastern parts of Britain and below average in most western areas, but they may also be near or above normal in north-west Scotland.
High pressure is forecast to just about hold on in eastern Britain on the 25th (the Bank Holiday Monday) bringing dry and bright weather, with sunshine coming through for many, but with cloud and rain probably arriving in western areas late in the day. This will be associated with a change to far more unsettled conditions as we head through the rest of August. Some bands of rain are expected to push from south-west to north-east, interspersed with brighter, showery weather, and with potential for low pressure to become quite slow-moving over and to the west of Britain, there may be some heavy and thundery showers at times, especially in the south of Britain. There is also potential for strong winds around midweek.
Winds will often be southerly during this week, with lowest pressure often to the west, and this means that although it will be far more changeable and wet than of late, temperatures will generally be above average for the time of year, but not exceptionally so. Also, the north of Scotland, sheltered from the southerlies, may well miss the majority of the rain and showers.
Mean temperatures are forecast to be 1 to 2C above the 1991-2020 long-term normal for much of northern and eastern Britain during this week, but probably closer to normal in the south-west.
Rainfall is forecast to be above normal for most of the country, especially the south, but probably near normal in the northern half of Scotland, and potentially a bit below normal in north-west Scotland.
Sunshine totals will probably be close to normal overall in northern and eastern Britain, and perhaps rather above normal in parts of northern and eastern Scotland and north-eastern England, but below normal in most parts of Wales and south-west England.
During this period we will probably move into a more mobile, changeable westerly type with some warmer, humid tropical maritime west to south-westerlies alternating with cool, bright, showery north-westerlies. Temperatures are generally expected to be close to normal overall but they may be slightly above normal overall in parts of the south and east of England, where the warm humid tropical maritime air masses will visit most frequently. Rain belts will frequently move from west to east, with some brighter, showery weather in between, but brief ridges of high pressure may bring a day or two of dry and bright or sunny weather to the south on occasion.
It is generally expected to be wetter than average, but generally less wet than during Week 2, except in northern Scotland, where a relatively dry Week 2 will be followed by wetter weather in Week 3. Sunshine totals will probably be below normal for most parts of the country, especially in the west, but some sheltered eastern counties may see near or slightly above average sunshine.
Confidence is lower regarding this period’s weather, but the most likely outcome looks to be for low pressure and wet, changeable conditions to be more frequent than average, resulting in generally above-average rainfall for most of the country. There is potential for the south and east of England to be drier, with near average rainfall more likely for those regions. Temperatures are most likely to be near normal in western Britain, but parts of the east, particularly the south-east, may come out a little warmer than average again. Sunshine amounts are uncertain, as in this type of setup they can vary quite considerably depending on whether it is predominantly cloudy and wet or bright and showery, but the most likely outcome is below-average sunshine in the west and near average sunshine in the east.
Monthly weather forecast
The month ahead forecast is written by Ian Simpson and is updated every Monday.
