Weather maps indicate that temperatures could reach 29C in parts of the UK on September 15, but the Met Office has suggested that an official heatwave is unlikely as warm conditions are expected to be brief.
Temperature forecast for mid-September
According to WXCharts weather maps, which use Met Desk data, temperatures are forecast to climb to near 30C on Tuesday, September 15. By midday, areas in the south are expected to be around 27C, with London the hottest part of the UK.
Hertfordshire, Bedfordshire and coastal areas including Brighton are also forecast to reach 27C. In the north, it is expected to be colder, with Manchester and surrounding areas sitting at around 20C.
Evening peaks and regional variations
By 6pm, temperatures are expected to increase across the nation. London, Berkshire, Surrey and parts of West Sussex could climb to 29C in the evening. The maps also forecast that areas up towards Northamptonshire will reach 27C, while Oxfordshire is likely to reach 26C, with much of the Midlands sitting at 25C.
Further north in Greater Manchester and parts of Yorkshire, the temperature may increase slightly to 23C.
Heatwave threshold and long-range outlook
An official heatwave is declared by the Met Office when temperatures reach the "heatwave threshold" for three consecutive days. The threshold sits at 28C in the south-east, where conditions tend to be warmer, meaning on September 15 the temperature would meet the heatwave requirement.
However, as the warm spell is not expected to last, it is currently looking unlikely that an official heatwave will be declared. The Met Office's long-range forecast for September 6 to 15 states: "An unsettled period is likely, with many places seeing showers or longer spells of rain at times."
The forecast adds: "Rain will likely be most frequent across northern and western areas, while the south and east are more likely to see some drier interludes. There is also the potential for some strong and gusty winds, particularly in the northwest."
Temperatures are likely to be near average, although brief warm or very warm spells are possible, especially in the south.
