The good news for most visitors to Gran Canaria is that the south of the island, where all the resorts are, gets almost permanent sunshine. This is because the trade winds and their clouds blow from north to south and get diverted around the island by the central highlands. The south, in the shadow of the island, exists under a bubble of blue sky that only disappears when the winds change.
Maspalomas & Playa del Inglés
The sand dunes do their bit to keep Maspalomas beach and resort sunny. Even when most of the island is cloudy the dunes seem to burn off the cloud and create their own blue patch. Maspalomas is sunny for over 300 days per years and often goes for months without a cloudy day.
Arguineguin & Puerto Rico
Right in the shadow of the highlands these two south-west Gran Canaria spots get 320 days per year of blue sky. The beaches at Puerto Rico, Patalavaca, Amadores and Arguineguín are your best bet for sunshine even if the rest of Gran Canaria is cloudy (which isn't very often).
Puerto de Mogán
Puerto de Mogán is as sunny as it gets in Gran Canaria and the Canary Islands. With its little beach and marina perfect for strolling, it's an idyllic spot to enjoy the sunshine. It gets over 320 days of blue skies every year.
The Agaete Valley
The sunshine bubble over south Gran Canaria often extends all the way up the west coast to the Agaete Valley and Puerto de las Nieves beach. Even if Las Palmas and the whole of the north are in the clouds, Agaete is often sunny. It's why the valley is the only place in Europe where coffee grows. If you're staying in north Gran Canaria and want sunshine without too many other visitors, head to Agaete.
So the south is almost always sunny, except for the odd patch when the trade wind fades away or the wind blows from the south. What about the rest of Gran Canaria?
Well, the west coast is almost always in sunshine but unless you stay at La Aldea it's not that easy to enjoy.
The East coast of Gran Canaria is normally sunny south of the airport but is often completely blue.
The highlands or cumbres can be sunny, cloudy, hot and cold within a day. If the coast is cloudy and you have a car, head up into the mountains. there's a good chance you'll find sunshine above the clouds.
Even in the "cloudy" north you get some sunshine most days. Las Palmas has the world's most pleasant climate even if the odd week is cloudy.