Temperatures in the UK are forecast to climb as high as 28C (82F) on Sunday, marking a brief return of summer-like warmth. A southerly wind is expected to draw hot and humid air from continental Europe, pushing temperatures above the seasonal average.

The hottest conditions are anticipated in south-east England, where thermometers could reach 27C or 28C. Other areas across England and Wales are likely to experience temperatures in the mid-20s Celsius. This spell of warmth follows a period of intense heat in central and southern Europe, with some locations exceeding 45C.

High pressure building from the south is responsible for the warm air, with countries like France and Spain experiencing temperatures above 40C. Spain recorded its hottest day of the year on Thursday, with Huelva reaching 45.7C. These high temperatures are expected to persist in Spain and parts of southern France into the coming week.

For the UK on Sunday, an approaching low-pressure system over north-western Scotland will bring rain to the region and showers further south. However, a shift to a southerly wind will 'scoop up' the hot air from the continent. Sunshine developing across England, Wales, and eastern Scotland later in the day will contribute to the unseasonably high temperatures.

Average temperatures for early September in the UK typically range between 15C and 21C, depending on the region. The current forecast suggests that south-east England, central-southern England, and the Welsh Marches could see afternoon highs widely in the mid-20s, with some spots potentially reaching 28C. South-west England and eastern Wales may reach 25C, while northern England is predicted to be around the low 20s Celsius. Eastern Northern Ireland and the Moray Firth area in eastern Scotland could see highs of 21C or 22C.

However, this warm interlude is expected to be short-lived. As the high pressure moves eastwards, the low-pressure system will bring more unsettled weather. By Monday, strong winds are expected in north-west Scotland, with possible coastal gales. Showery rain will spread from west to east, and temperatures are predicted to drop behind a cold front by Tuesday.

Wednesday is forecast to be more settled with a brief return of high pressure, but it will remain cooler than the weekend's peak temperatures. The unseasonably warm conditions are a stark contrast to the drought conditions that have persisted in two-thirds of England, as evidenced by parched grass seen in London's Wimbledon Common.

Further details on the monthly outlook for September are available, with related stories touching upon why August can be rainier than September and warnings about a potential 'supersized' El Niño event.