Updated 3rd August - Covering the period 10th August to 1st September.
Mean temperatures will be above normal overall, by 1.5 to 2.0C in parts of eastern and central England, but by less than 1.0C in Northern Ireland and in parts of south-western Britain. Most other regions will be between 1.0 and 1.5C above.
Rainfall totals are generally expected to be below normal, but in the northern half of Scotland they will tend to be near normal, and they may be raised above normal locally, especially in the south and west, by localised thundery downpours in Week 2.
Sunshine totals will tend to be above normal, especially over much of England, the south and east of Wales and also in south-west Scotland, but they are likely to be close to normal over much of the northern half of Scotland.
The early to middle part of this week will feature plenty of hot dry sunny weather for most of the country. It will be particularly hot in central, south-eastern and north-western England, where temperatures will widely reach the high 20s Celsius, with potential for temperatures to reach the low to mid 30s in places, especially in the south-east. It will also tend to be very warm or hot in western Scotland. However, a generally easterly or south-easterly flow will bring suppressed maximum temperatures near North Sea coasts, with potential for low cloud to affect eastern Scotland and north-east England, especially near the coast. Some thundery outbreaks may affect southern parts of Britain, associated with relatively low pressure to the south.
The fine weather will probably break down from the west towards the end of the week, with potential for thunderstorms but considerable uncertainty over where and when any thunderstorms will hit, followed by rather cooler weather and shallow low pressure.
Mean temperatures are thus expected to be somewhat above the 1981-2010 long-term normal over much of the UK, with positive anomalies of 3 to 4C over much of England and also parts of western Scotland. Most other regions will have positive temperature anomalies of 2 to 3C, but the far south-west and the north-east coast will tend to be just 1 to 2C warmer than average.
Rainfall totals will generally be below normal, although locally, especially in the west and south, they may be raised above normal by thundery downpours.
Sunshine totals will mostly be above normal, particularly in western Scotland and north-west England, but there is potential for coastal parts of the north-east to see below average sunshine, depending on how moist the continental air masses are (if they are moist, low cloud off the North Sea will be a frequent issue).
Following the breakdown at the end of Week 2, a north-south split is expected with the Azores High frequently ridging into southern parts of Britain, but the north-west will be more exposed to wet and windy weather coming in off the North Atlantic. As a result, a fair amount of sunny and dry weather is expected over central and southern parts of England and south Wales, with just brief interruptions, while over much of Scotland and Northern Ireland the weather will be more unsettled.
With mostly westerly winds, mean temperatures will be much closer to the long-term normal during this week, though still on the warm side in eastern and central England in particular, and near normal in most parts of the west. Rainfall totals are again expected to be mostly below normal, except in the northern half of Scotland. Sunshine totals will tend to be above normal over most of England and in central, southern and eastern parts of Wales, but are more likely to be near normal over much of Scotland and Northern Ireland and in parts of north Wales and north-west England.
The general north-south split pattern is mostly expected to continue but a more widespread spell of warm, potentially hot, dry sunny weather is expected to extend across the country for a few days, most likely early on in the week, with high pressure heading further north across the country. Some cool nights are expected towards the end of this period. Mean temperatures are expected to be close to or slightly above the long-term normal overall during this period, with some fairly cool nights offsetting warm days. Most parts of the UK will probably be drier and sunnier than average again, but confidence in this is relatively low for the northern half of Scotland.
Monthly weather forecast
The month ahead forecast, written by Ian Simpson is updated once a week - every Monday. As with any longer term forecast, it's not possible to go into much detail and accuracy can tend to drop off toward the end of the period but it can still act as a very good guide to the weather during the upcoming month.