Wednesday
A hot and humid day as a southeasterly airflow prevails, dragging in the air from the near continent. Dry and sunny for most, although quite hazy skies. Thickening cloud in the southwest of England brings an increasing risk of rain spreading from the south, some thundery bursts developing, these advancing north into Wales later in the day. Thicker cloud in western Scotland may also produce a spot of rain. Mostly light winds, gusty locally for Wales. Highs 25 to 30C.

Wednesday night
Staying warm and humid into the night. Many places dry, but southern and western parts of England & Wales have a greater risk of thundery rain drifting northwards, quite hit and miss but some heavy downpours are likely. By dawn, a zone of thundery rain is likely to lie across the Midlands, edging north into Pennine areas. Further north and east generally dry with some mist patches forming. Winds mostly light. An uncomfortable night, only dropping to 14 to 18C.

Thursday
Low pressure dominates the scene on Thursday, bringing a more mixed day with outbreaks of rain, some thundery. The rain may turn heavy and persistent at times for some. Rather cloudy, however, sunny spells are expected across parts of England and Wales and particularly the southeast where temperatures will be very warm again. Highs up to 27C in the southeast, generally elsewhere highs between 17 to 25C, cooler again across northern Scotland.

Friday
A shallow area of low pressure is due to lie just east of Britain. Showery bursts of rain are likely, these could be heavy in places, mainly eastern Scotland and eastern England as far south as about Lincolnshire. A scattering of showers are likely to drift from Wales into the Midlands. Rather cloudy for most but some sunny intervals, best toward southern coasts. Reasonably mild for the south and east with highs at 24C, cooler north and west at 17 or 18C.