Saturday 20th June
The heat was beginning to build on Friday that gave us the hottest day and night this month. The thermometer rose to a maximum of 25.7C at 14.12 before variable cloud limited any further rise but this was 5C above my long-term average and made to the hottest day since 28th May. The overnight cloud limited the loss of warmth into the atmosphere resulting in a very mild night, in fact the warmest night this year with a minimum of 16.4C at 23.59 being 6.2C above average.
Saturday began with total cloud cover, in fact an area of thicker cloud passed our way at 07.30 that produced misty conditions over the higher ground, being due to a weak weather front crossing southern England this morning. Today will be the last of the very warm, cloudy days before heatwave conditions arrive on Monday.
The barometric pressure has begun to rise as the anticyclone to the south edges our way. The plume of very hot air over the Continent will continue to push northwards that will bring intense heat on Monday and for the rest of the week. An official heatwave for Wiltshire is three consecutive days when the maximum temperature equals or exceeds 27C. The forecast is for all days next week to exceed that threshold which will make it an official heatwave.
As we move into next week the area of high pressure will extend from north Africa to Scandinavia. This will result in the breeze arriving predominantly from the southeast bringing the very hot air. This process will begin on Sunday as the wind direction will rotate clockwise for 180 degrees, from west to east and southeast, as the day progresses.
Amber extreme heat warning issued with heatwave forecast for many
Author: Met Office 11:08 (UTC+1) on Fri 19 Jun 2026
Updated at 11:08 (UTC+1) on Fri 19 Jun 2026
The Met Office has issued an Amber extreme heat warning for much of southern England and southeastern Wales, with impacts to people and infrastructure possible at the start of next week and water safety a particular concern.
A heatwave, centred around southern and eastern England initially, is developing over the weekend and will continue into the start of next week. The Amber extreme heat warning coincides with what’s expected to be the peak of the heat through Monday and Tuesday, when temperatures are likely to reach 34°C, though there remains a chance of this being exceeded in some spots.