13/07/2026 – Weather in Cornwall

Cornwall heatwave to hit 32°C before thunderstorms move in

If you have been planning your week around the sunshine, keep an eye on the sky. The heat is staying put across Cornwall and the wider South West, but the forecast for the second half of the week comes with a warning attached: showers and thunderstorms are creeping into the picture.

A hot, breezy start to the week

Monday brings a largely dry, sunny and hot day, with temperatures climbing to a maximum of 31°C. There is a small chance of a few showers developing along the south coast later in the day.

It will be widely breezy, and strong winds are set to continue along the south coast. So if you are heading for the water, the heat may not feel quite as still as the numbers suggest.

Overnight, there is a risk of some further showers towards Devon and Cornwall. Otherwise it stays warm and dry with plenty of clear skies, and it remains breezy near the south coast. The minimum temperature is expected to be 15°C, which makes for another uncomfortable night for anyone trying to sleep without a fan.

Tuesday could be the hottest day

Tuesday is forecast to be another hot day, with a maximum temperature of 32°C. The sunshine is likely to be hazier than it has been in recent days, and there is a small chance of the odd shower in the west, though most places should stay dry.

Thunderstorm risk builds later in the week

From Wednesday through to Friday, it stays hot with plenty more sunshine. But the risk of showers and thunderstorms increases at times.

Winds are also expected to be lighter than on Monday and Tuesday, which will add to the hot feel. Less breeze means less relief, and it also means the heat will sit heavier through the middle of the week.

What that means for you

The headline for the week is simple. The heatwave continues, and there is a small risk of thunderstorms.

If you are working outdoors, walking the coast path, or planning a beach day, the hottest part of the week arrives early and the most unsettled part arrives late. Wednesday to Friday is when a sunny morning is most likely to turn into a rumble of thunder by the afternoon.

Keep water with you, keep an eye on children and older relatives, and if you are on the south coast this week, respect the wind as much as the heat.