New weather maps from WXCharts, generated using Met Desk data on July 7, indicate that parts of the UK could see temperatures drop to as low as 4C later this month, marking a sharp contrast to the ongoing heatwave. The ECMWF forecast maps show much cooler air sweeping across the UK by the early hours of Tuesday, July 21, with overnight temperatures falling into single figures across much of the country.
Heatwave to End with Dramatic Cool-Down
Britain is currently experiencing its third heatwave in seven weeks, with temperatures forecast to reach 34C or even 35C in parts of southern England later this week. However, forecasters have noted that this spell will not be as hot or humid as the record-breaking conditions seen in June. The latest forecast maps point to a dramatic cool-down, with the coldest conditions expected in the Scottish Highlands, where minimum temperatures could plunge to around 4C by 6am on July 21.
North-South Temperature Split
The maps suggest a clear north-to-south split, with the chilliest conditions confined to Scotland and northern Britain, while southern counties hold onto comparatively milder nights. Large parts of Scotland could wake up to temperatures between 5C and 8C, while northern England, Wales, and parts of Northern Ireland are also set for a notably chilly start to the day. Further south, much of England is forecast to record overnight lows of between 9C and 12C, with southern coastal counties expected to remain in the low to mid-teens.
22 Coldest Counties Identified
The full list of the coldest counties includes: Highlands, Moray, Aberdeenshire, Angus, Perth and Kinross, Stirling, Argyll and Bute, East Ayrshire, South Ayrshire, Dumfries and Galloway, Na h-Eileanan Siar (Western Isles), Orkney, Shetland, Inverclyde, Renfrewshire, North Lanarkshire, South Lanarkshire, Scottish Borders, Cumbria, Northumberland, County Durham, and Powys. According to the WXCharts forecast, these areas are most likely to experience single-digit overnight lows on July 21.
Atmospheric Patterns Driving the Cold
Forecast charts showing conditions higher in the atmosphere indicate a pocket of colder air pushing south across the UK, further reinforcing the cooler start to the day across many northern areas. The temperature gradient shown on the maps suggests that the chill will be most pronounced in Scotland and northern England, with the south remaining relatively mild. The Met Office has previously urged households to stockpile one item ahead of the cold snap, though no official warnings have been issued yet for the July 21 date.
