OK so you can't go sunbathing, but there are still plenty of enjoyable things to do in North Cornwall in wet weather.
Chances are if it's raining it might also be windy, and where there's wind there's waves. So why not jump into a wetsuit and go surfing? If you're going to get wet anyway, who cares if it's raining? The water temperature changes very slowly (over months rather than hours) so a bit of cloud doesn't make the sea any colder. In Summer or Autumn you should be nice and warm with a wetsuit. See our surfing section for more info.
If there is no wind and the sea is calm so surfing isn't an option, why not go snorkelling instead? The visibility won't be quite as far as on a bright sunny day but that works both ways - it might well allow you to get closer to wary fish like bass than when they can see you coming from miles off. You'll want to wear a wetsuit as you won't be heated from above by the sun, but with a full length wetsuit you should be nice and warm in Summer or Autumn. See our snorkelling section for some suggestions of places to go.
If the sea is calm, and there's a bit of light rain, then you won't really notice it when you are sea kayaking as you'll be wearing a wetsuit anyway. Not recommended if it's really foggy, but otherwise even in quite heavy rain you can have a perfectly pleasant outing. As you are not immmersed in the water then in Spring, as well as Summer and Autumn, a wetsuit will keep you warm and protect you from any wind and rain. See our kayaking section for some suggestions of places to go.
If the weather is showery you might be able to fit in some short walks between showers. If you're walking near the coast you can often see a shower coming in over the sea from the west so you get a couple of minutes advance warning to take cover. We've collected some walks of between 0.5 and 2 miles on our short walks page. If there is a strong westerly wind then there is often impressive sea foam at Backways Cove and seals can often be seen along the Tintagel and Boscastle coast sitting out the storm in the bays. If it's wet, watch out for slippery paths; if you wear walking boots with a good grip you should be OK.
In you're interested in historic buildings, many of these can provide a refuge on a rainy day. Some that are particular good in wet weather are:
If it's showery you may be able to take cover inside, and explore the gardens between showers. See our historic buildings section for more details.
Within half an hour to an hour's drive there are a number of National centres of excellence ranging from the Eden Project to the National Aquarium which are genuinely worthwhile and interesting places to visit and perfect for a rainy day. Many also run special events (they have programmes listed on their websites) which range from activities for children to dinners and cruises. See our section on indoor attractions for some more detailed information.
One of the nicest ways to warm up after braving the wet weather is in front of a roaring fire with a fortifying drink. The Port William overlooking Trebarwith Strand is particularly good as it has large windows through which you can watch the wild weather and sea crashing onto the rocks at Trebarwith. You can also easily get out for a walk on the beach in between downpours.
If it's showery, you might want to explore some of Cornwall's ports such as Boscastle, Port Issac and Padstow which have some nice old pubs you can take refuge in during a shower and some other interesting history to explore in between downpours. Some leaflets for "town trail" walks are available from the Tintagel Visitor Centre which describe the history around you.
There is more to food in Cornwall than pasties and cream teas! There are some great places to sample and buy food nearby such as Deli Farm charcuterie who produce a whole range of salamis and cured meats, Camel Valley Vineyard who produce highly acclaimed English wine, and Granny Wobbly's Fudge Pantry where home made fudge is made on a slab within the shop. See our food and drink section for more information.
You may also want to nip out between showers or put on your waterproofs to do a quick bit of forraging to make a warming meal. On a low spring tide you can harvest some quite big mussels at Hole Beach. Also at Trebarwith Strand you can harvest the young shoots of bladderwrack seaweed which makes a great noodle soup with some fresh ginger.
Some other websites with ideas for things to do on a rainy day are: