8 common MYTHS about Cornish weather DEBUNKED
Take a look at a map of the UK, and follow it to the South West.
That’s the rugged peninsula of Cornwall, jutting out from the UK into the Atlantic Ocean. A Duchy enveloped by roaring waves, pointing south into the jet stream but at whim to the ocean’s temperament.
Cornwall’s geography goes some way to explain how its weather is different to the rest of the UK – but let’s delve into exactly why by debunking some of the common myths told about Cornish weather.
These are…
1. It’s warmer than London
Whether this is true depends on the time of year!
Cornwall is usually warmer than London in the winter – although often not markedly.
Often, temperatures in London may hover around freezing, whereas in Truro they could be a few degrees warmer. This is thanks to the jet stream, which keeps the peninsula of Cornwall toasty in the winter season.
But in the summer, that jet stream (and the Urban Heat Island effect) causes Cornwall to be a bit cooler than London!
Most notably, once in 2022, the barometer in London hit 40 degrees, whereas in Cornwall it was a much more pleasant 27 degrees.
2. Cornish mizzle is just light rain
If you aren’t from Devon or Cornwall, you might not have heard of mizzle.
It’s a West Country phenomenon, mixing drizzle with a sticky, clammy fog.
And it has a habit of getting you drenched.
While it’s definitely not as dramatic as storms, don’t underestimate Cornish mizzle!
3. It never snows
Cornwall’s milder climate means snow is rare, but it does happen.
Higher ground, like Bodmin Moor, is the most likely place to see a dusting, and when it does snow, it can cause significant disruption – mostly because it’s so unexpected!
Even coastal towns have seen snowfall, though it’s often fleeting.
There was a fair amount of snow in January 2025, but before that the last widespread snow covering was the “Beast from the East” in 2018.
4. Storms aren’t that bad
Cornwall is one of the windiest places in the UK, and when a storm rolls in from the Atlantic, it’s a force to be reckoned with!
Gusts of over 80mph aren’t uncommon, especially along the north coast where exposed cliffs bear the brunt of the weather.
In fishing villages and harbours, high tides combined with storms can lead to waves crashing over sea walls and flooding roads.
If you’re in Cornwall and it’s stormy, stay away from cliff edges, stay inside if possible and keep up to date with any warnings or alerts.
5. The sea is never swimmable
Cornwall’s waters might not be as warm as the Mediterranean, but they’re swimmable for much of the year – especially for those accustomed to colder seas!
In summer, water temperatures reach around 18°C, and in sheltered coves, the sun can warm the shallows considerably.
Even in winter, some brave swimmers take to the sea – and the popularity of seaside saunas make it much more comfortable!
Just be aware that currents and tides can make conditions dangerous in certain spots and lifeguards don’t operate in the winter.
6. All beaches are great for surfing
Cornwall has some of the UK’s best surf, but not every beach is ideal for catching waves.
Some, like Porthcurno or Gyllyngvase, are better for swimming and paddleboarding than surfing.
Others, like Fistral or Perranporth, are famous for their consistent waves.
The south coast tends to be calmer, while the north coast gets the full force of Atlantic swells.
Conditions also change with the seasons – winter brings bigger waves for experienced surfers, while summer tends to be better for beginners.
See my full guide to surfing in Cornwall.
7. Cornish weather is the same all over the Duchy
The weather in Cornwall can vary dramatically from one place to another.
The north coast is more exposed to Atlantic winds – meaning it’s often cooler and windier than the south.
Inland areas like Bodmin Moor can be noticeably colder, especially in winter.
Meanwhile, the far west, around Penzance and the Isles of Scilly, tends to be the mildest part of Cornwall, with palm trees growing in sheltered spots thanks to the warming influence of the Gulf Stream.
It’s often suggested that if you’re holidaying in Cornwall and don’t like the look of the weather, just drive up the road and it may well be different!
8. You should trust the weather forecast
Weather forecasts for Cornwall can be hit or miss, especially beyond a day or two.
Thanks to the ever-changing Atlantic conditions, forecasts can shift quickly, and a day predicted to be dry can suddenly turn wet!
Microclimates also play a role—while it might be raining in Newquay, it could be dry in Falmouth.
The best approach? Plan for everything – and always enjoy blue skies and sunshine when you can!
Take a look at my other Cornwall posts to help plan your trip: