BBC monthly outlook
Summary
A cooler start to June, but some warmer air later
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Saturday 1 June – Sunday 9 June
Warm weekend, then cooler next week. Wet.
June will start off with a warm but wet weekend as a frontal system sweeps across the country. Much of the southern half of England and Wales will see above average temperatures Saturday, with the Southeast seeing them Sunday as well. Highs are expected to climb into the upper twenties. Further north, however, lingering fronts will keep things wet, cloudy, and with temperatures near or a touch below average. Rain is expected to be heavy at times, especially in the west and for much of Scotland, while western counties of England and Wales turn breezy Sunday night into Monday as the cold front passes.
Moving into the first full week of June, the jet stream is expected to dip south into Spain and France, taking the warmer summer air with it. The working week is expected to be near or a bit below average, with the warmest weather staying in the South. Low pressure nearby will keep things unsettled with scattered sharp and at times thundery showers drifting in from the west or southwest. Tuesday afternoon a low moving in from the southwest will bring some heavier showers to most of the country, lasting through Wednesday. The best of the dry and sunny spells will be in the East, but there will still be some glimpses of sunshine in the West.
Heading into the next weekend, there is increasingly strong signals in the models that a low may develop in France and track quickly north into the North Sea through Saturday and Sunday. This would bring in some quite heavy rain and thunderstorms along with some very warm air to the Southeast and East, but there is still some uncertainty on how far west the rain will get, and it may well stay offshore.
Monday 10 June – Sunday 16 June
Becoming drier and gradually warmer for a time.
During the first week of June high pressure is expected to build strongly in Eastern Europe, keeping their weather settled and warm in a more typical summer pattern. By mid-June, this high is expected to slowly shift northwards into both Scandinavia and the UK, allowing us to experience some of the sun and warmth too. This will be a gradual transition after a rather wet weekend for some, so early in the week expected some showers to linger in the West and South before they are pushed off by the approaching high.
After a cooler start everyone is expected to warm to above average, with the warmest weather being in the eastern half of the country. As the high shifts northwards, Scotland will turn very dry with mostly sunny skies and some very warm days expected. Low pressure to the south will mean that there may be occasional cloudy spells for the southern half of England. Although it looks to be warmth and mostly sunny, the prospect of any significant and sustained hot weather is rather low.
Monday 17 June – Sunday 30 June
Staying warm, but rain expected to return.
High pressure will likely remain a significant weather feature for a significant portion of the third full week in June, however it will begin to slowly retreat eastwards again. A mostly sunny and warm start will therefore gradually transition into a more unsettled and less warm finish for the first month of meteorological summer. Temperatures are still expected to be a bit above average as the low pressure centres will tend to stay to the northwest, dragging in some warmer tropical air from the Azores. The wettest weather in this pattern would be expected in the South and Southwest, with the lingering effects of the high keeping northern areas largely dry and fine.
The main uncertainty for the second half of the month is exactly where the high will end up, and this is largely down to what is happening across the pond in the United States. Temperatures are expected to be cooler than normal in the southern and eastern half of the US, which will result in a stronger-than-usual jet stream over the Atlantic that may help strengthen the trough of low pressure in Western Europe that will bring us our unsettled weather.
This volatile jet stream will have a major role in the UK's late-June weather, so confidence is still low at this point, although there are not any strong indications of sustained cold anywhere. The main alternative scenario is for the high to shift northwest of the UK towards the end of the month, bringing in some cooler (but not cold) northwesterly winds and bringing wetter and windier weather to the North.
Further ahead
As we near a potentially very wet and stormy weekend in early June we can try and pin down who might want to re-think their outdoor plans or pack an umbrella.
https://www.bbc.co.uk/weather/outlook