Updated 27th June
Covering the period 4th July - 26th July
Changeable and quite cool
It will be on the cool side, with mean temperatures generally about 1C below the 1981-2010 average. The negative anomaly will generally be larger by day than by night.
Rainfall totals will be close to normal in the north and west of Scotland and in south Wales and south-west England, but it will be wetter than average elsewhere, especially eastern England and south-east Scotland where many places will have over 50% more rainfall than usual.
Sunshine totals will mostly be slightly below normal, but a considerable shortage of sunshine is expected in eastern Scotland.
Monday 4th July - Sunday 10th July
This week will be dominated by mainly westerly winds with weather systems coming in off the North Atlantic at frequent intervals, especially in the second half of the week.
A belt of rain will move eastwards across much of the British Isles early on the 4th, probably especially affecting central and southern parts of Britain, with brighter showery weather following behind from the west. A weak ridge of high pressure will spread from the south-west on the 5th and 6th, with light winds, so the 5th will be a bright and showery day for most, with scattered weak thunderstorms, these mainly in eastern England. The 6th will also be bright and showery, but with generally fewer showers, especially in the south. However, it will turn cloudy and wet on the 7th as the next weather system spreads in from the west.
The 8th and 9th July will tend to be cloudy with some showers or longer spells of rain, and it will be rather breezy with winds swinging around to a northerly direction for a time. A brief ridge of high pressure ahead of the next weather system may give a relatively dry and bright day for most parts on the 10th, but there is uncertainty over the timings of weather systems at this range.
Temperatures will generally be a degree or two down on the 1981-2010 long-term average, with a similar negative anomaly by day and night. Rainfall totals will be below normal in the north and west of Scotland but above normal elsewhere, with central and eastern England likely to be particularly anomalously wet. Sunshine totals will be above normal in north-west Scotland and slightly above normal in Northern Ireland, but near to slightly below normal in most other parts of the UK.
Monday 11th July - Sunday 17th July
There won't be much of a let-up in the westerly pattern this week, with Atlantic weather systems continuing to move freely from west to east, and often rather to the south of their usual position. It will tend to be cloudy for most parts of the country with showers and longer spells of rain, and only very brief ridges of high pressure in between the weather systems. Late in the period, pressure will rise over the eastern North Atlantic resulting in quieter weather and a generally north-westerly flow, although it will remain predominantly cool and cloudy in most regions, with the south-west seeing the brightest conditions, nearest to the high pressure.
It will remain on the cool side, though not exceptionally so, with mean temperatures coming out about 1C below the long-term average in most regions. Rainfall totals will be close to normal in northern and western Scotland and in south-west England and south Wales, but it will be wetter than normal elsewhere, with eastern England again likely to have the largest excesses. Sunshine totals are expected to be well below normal in eastern Scotland, and near to slightly below normal in most other parts of the UK.
Rest of the month
Monday 18th July - Tuesday 26th July
Into late July, changeable westerlies are still expected to be the dominant pattern. It will be relatively anticyclonic early in the period, with ridges of high pressure covering the south at times, giving a north-south split with drier brighter conditions in the south and cloudy conditions in the north with some rain at times. Cloudy conditions will also spread down the eastern side of England, associated with northerly and north-westerly winds. Later in the period, low pressure will start tracking further south than usual again, resulting in frequent rain or showers in all parts of the country, and generally cloudy conditions.
Temperatures will mostly be within a degree of the 1981-2010 average during this period, but over 1C below in the north and east of Scotland. Rainfall totals will be above normal except in south Wales and southern England, where they will be close to normal. Sunshine totals are expected to be near normal over much of England, Wales and Northern Ireland, and below normal over much of Scotland.