Bouts of rain, heavy and thundery at times, will move in from the west during the early hours of Wednesday.
Temperatures have dropped by 10C today after three days of scorching sunshine but they will creep back up to 25C tomorrow.
And while the south coast basks in temperatures of up to 34C, Yorkshire will be hit by thunderstorms on Wednesday and Thursday.
The heatwave will come to an end in our part of the world with torrential downpours, hail and lightning.
Heatwave: How hot does it need to be before you can ask your boss to go home?A Met Office spokesman said: "More extensive thunderstorms may then break out over a larger part of England and Wales from late Wednesday afternoon onwards into Wednesday night, leading to torrential downpours, frequent lightning and a chance of hail.
"This could result in some disruption, more likely from late Wednesday afternoon, which may include sudden localised flooding of transport routes, homes and businesses. Frequent lightning in association with the heaviest rain may also temporarily disrupt power supplies. However, many places will likely see little or no impacts. Indeed many parts of the warning area will see dry and sunny weather through much of the daytime on Wednesday."
The full Met Office forecast for Yorkshire:
Dry but feeling noticeably cooler everywhere as there will be large amounts of low cloud spreading south this morning, although some bright or sunny intervals gradually develop later. Hill fog and coastal mist at times, especially this morning. Maximum temperature 22C.
Generally large amounts of cloud, but some clear spells are possible at first. Overnight there is a chance that isolated heavy showers or thunderstorms may arrive. Minimum temperature 11C.
Areas of low cloud will burn away to leave bright or sunny spells. Risk of isolated very heavy thunderstorms, mainly early and late, otherwise dry. Highest temperatures across the south. Maximum temperature 25C.
Outlook for Thursday to Saturday:
Much fresher but bright with temperatures closer to normal, and often breezy. Thursday and Saturday there will be sunshine and isolated showers. Friday cloudier with rain at times.