20/05/2026 – Weather in Cornwall

Cornwall Set for Scorching Bank Holiday but There’s a Catch

After a grey and unsettled start to the week, Cornwall is about to get the kind of weather that empties offices and fills beaches. The forecast for the coming days points to rising temperatures and plenty of sunshine, with the Bank Holiday weekend tipped to be a warm one. But it may not be entirely smooth sailing.

A cloudy start that gets better

Wednesday begins largely cloudy across the South West, though brighter spells are expected to break through as the day goes on. A few spots of rain are possible where the cloud thickens, and while it stays breezy, it should feel pleasant in any sunshine. Temperatures are due to reach a high of 18°C.

Overnight, any showers will largely ease away to leave a dry but cloudy night. The blanket of cloud is expected to keep things mild, with the temperature not dropping below 9°C.

Warming up on Thursday

Thursday opens cloudy with a few outbreaks of rain in the morning, but the picture improves later. The rain is expected to clear and skies will brighten a little in the afternoon, bringing some warm sunny spells. The high climbs to 22°C.

Very warm for the long weekend

The headline is reserved for Friday through to Sunday. Forecasters say it will be very warm over the Bank Holiday weekend, with plenty of sunshine and light winds.

There is one note of caution, though. Some heavy, thundery showers are possible on Saturday, so anyone planning a full weekend outdoors may want to keep half an eye on the sky.

The forecast was last updated at 04:00 on Wednesday 20th May 2026.