BBC monthly outlook
Summary
Unsettled at first. Drier late March into April
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Saturday 14 March – Sunday 22 March
Further rain for a time but settling down later
Over the weekend a weather system is expected to move across the country, bringing some heavy rain to northern and western areas on Saturday. Southern and eastern areas will stay mostly dry. By Sunday the rain will arrive here too, as a cold front heads southeast. Behind the front, high pressure will build in from the west with some cooler-feeling air.
For the first half of next week, there will be a bit of a north-south split in the weather for the UK. A frontal system will push into northern areas on Monday while high pressure keeps the southern half of the country fine, mild and dry. A weak front will slowly make its way southwards but it is unlikely to reach southern England until later on Wednesday. This will keep southern areas on the warmer, drier side of the front through midweek. Northern areas will be cooler but also fairly dry. Outbreaks of light rain are expected along the front, mainly in the Midlands.
The second half of the week and next weekend will see high pressure build in strongly from the northwest, pushing the weak front into Central Europe. Turning much drier throughout the country, with some sunny days, chilly nights and frosty mornings. There is a risk for a few showers along the east coast at times but these are not expected to push too far inland.
Monday 23 March – Sunday 29 March
Dry weather for many but some rain in the north.
The colder but drier end to next week will likely continue into late March as high pressure is sluggish to move away. However, this sustained dry period will bring some relief to flooded areas after the extremely wet winter. Temperatures will tend to be a bit below average for the start of the week, especially in the east where a brisk northerly wind will persist on the North Sea. But lighter winds for central and western counties will make for pleasant-feeling afternoons, despite the cooler air. Overnight it will continue to be chilly and some frosty mornings are likely throughout the country.
Later in the week, Atlantic weather fronts are likely to creep back in from the northwest, reaching Northern Ireland and northern Scotland. This will make for a wetter and windier close to the month for these areas but fronts will likely be on the weaker side so rain shouldn't be too heavy. However, this will also bring in some southwesterly winds that will help drag in warmer sub-tropical air into the UK, so the end of the week will turn milder.
Confidence for the end of March is overall pretty high with the models performing well recently. The main risk to the forecast is that high pressure stubbornly remains in place, preventing fronts from arriving. This will be a drier and calmer pattern for the north and west but it will also keep things cooler than normal.
Monday 30 March – Sunday 12 April
Spring-like days, chilly nights. Wet in the north.
As we head into April, the weakening high pressure is expected to make a comeback for a time, with the first part of the month seeing dry, calm and mild weather throughout. Weak fronts may be able to find their way into Scotland at times but there will be some lengthy dry spells here too. Temperatures will tend to be a bit above average for many however, western areas will tend to be nearer to normal.
Prolonged high pressure also means clear, calm nights, so it is likely the mornings will feel quite crisp. Frosts are still expected during some nights, even in the south but the days will quickly warm up in the mostly sunny afternoons. Pollen levels will begin to climb as well with some very spring-like weather.
Towards the middle of the month there are some early signs of a pattern change as high pressure declines slightly over northwest Europe. This means that Atlantic weather systems will begin to reach northern areas and possibly western areas too. Rain and winds will return but the winds will also stay mostly out of the southwest, so it will continue to be a bit milder than normal. The nights could be chilly but there will be a reduced frost risk.
However, confidence is low at the moment for high pressure declining and just how far south across the UK the fronts will reach. Southern areas may stay fairly dry and warm through mid-April but if high pressure retreats too quickly it could turn wet and windy again.
Further ahead
We will have some addition data for April to investigate how long high pressure may stick around into mid-month.
https://www.bbc.co.uk/weather/outlook