Cornwall weather by month

When to go to Cornwall

For beach weather, look at months where the daytime average clears 25°C and rainy days stay low: none reach a 25°C average here, so Cornwall suits city breaks and walking more than beach holidays; the warmest is July. December is the wettest month (100 mm, about 16 rainy days) and May the driest (64 mm). The sea is warmest in August at 16.6°C and coolest in February at 9.1°C.

Getting there

A direct flight from London Gatwick to Cornwall Airport Newquay (NQY, 6 km from Newquay) takes roughly 1 h 12 min - short-haul (up to 4.5 h) by UK standards. Time-zone: Europe/London.

Records and extremes, 1991-2020

The hottest day recorded in Cornwall between 1991 and 2020 reached 27.8°C on 18 July 2006; the coldest fell to -6.4°C on 7 February 1991. In July one day in ten tops 22.6°C, but 30°C days are rare; in February one night in ten drops to 0.6°C or below. The wettest single month of the period was November 2019 with 202 mm, against a November average of 97 mm.

Winter: mild temperatures, but limited sunshine

December, January and February suit travellers who can adapt their plans rather than depend on long spells outdoors. December averages 10°C by day, slipping to 9°C in January and February, so a warm layer and waterproof coat matter more than lightweight holiday clothes. Nights average 5°C in January and February, making evening outings noticeably chilly. December and January each have 16 rain days and just 2 hours of sunshine a day on average. February offers a little more sunshine and fewer wet days, but not warmer weather. The sea is cold throughout, so winter is a poor choice for casual swimming.

Spring into June: improving weather, with a cold sea

March is still cool at 10°C by day, so treat it as walking weather with warm layers rather than the start of beach weather. April's 12°C and longer sunshine average make outdoor plans more appealing, though rain remains a regular possibility. May reaches 15°C and has the lowest rainfall total, but still averages 13 rain days: driest does not mean reliably dry. June is the stronger choice if you want milder evenings and more time in the sun, averaging 6 sunshine hours daily. The catch is the water: even in June, the sea averages 14°C, so a wetsuit is sensible for longer swims.

Summer into autumn: warmth peaks before the sea cools

July and August are the warmest choices, both averaging 19°C by day and 14°C at night. That suits travellers who prefer moderate warmth to intense midday heat, though a layer is still useful for evenings. August has the warmest sea at 17°C, but even then the water can feel cool. Keep waterproofs handy: neither month offers dependable dry weather. September holds onto much of summer's warmth and averages 11 rain days, the lowest monthly figure, making it a strong option for outdoor plans. October drops to 15°C by day, with more frequent rain and less sunshine, so leave room to rearrange activities. By November, daytime temperatures average 12°C and sunshine is limited; choose it for a flexible break rather than a holiday built around being outside.