It does rain in Crete. Most often November through March, but brief summer storms happen too. A rainy day does not have to mean a wasted day. Here is what actually works.
Archaeological museums
Heraklion Archaeological Museum: The most important Minoan collection in the world. Frescoes from Knossos, the Phaistos Disc, the bull-leaping fresco. Budget 2-3 hours. Admission about 15 EUR (check locally). Open year-round, closed Mondays in low season.
Chania Archaeological Museum (in a converted Venetian church, the Agios Fragkiskos): Smaller but excellent, Roman and Byzantine finds. About 4 EUR admission.
Sitia Archaeological Museum: Minoan finds from the far east of the island, less visited, genuinely interesting. Free entry some Sundays.
Minoan palaces (partial cover)
Knossos is largely unroofed but the main palace areas are substantial ruins -- a rainy day actually reduces crowds significantly. Bring a waterproof jacket. Same logic applies to Phaistos (90 km from Heraklion, on a hilltop with views toward the Libyan Sea).
Byzantine churches
The Lasithi Plateau and the Amari Valley are dotted with small Byzantine chapels, many 13th-14th century, with well-preserved frescoes. Some are locked; ask at the local kafeneion for the key-holder. This is worth doing in any weather.
Old towns
Chania old town: The Venetian harbour, covered market hall (Agora), leather goods street, and multiple small museums (Maritime Museum, Cretan House Folklore Museum). A full day itinerary just from the old town.
Rethymno old town: Venetian Fortezza (partially covered), old town lanes, local shops. Good kafeneion culture.
Cretan cuisine activities
Several operators offer cooking classes year-round: olive oil tasting, traditional bread baking, Cretan cheese making. Prices vary (30-80 EUR per person). Search locally -- most are informal and not heavily marketed online.
Wineries
Crete has an underrated wine scene. Lyrarakis Winery (Alagni, 20 km from Heraklion), Douloufakis Winery (Dafnes), and Minos Palace Winery offer tastings. Most require an appointment in low season. The local Vidiano and Kotsifali grapes are worth knowing.
Olive oil mills
October through January is olive harvest and pressing season. Many mills welcome visitors informally. Ask your accommodation to point you to a local mill -- this is one of the more authentic agricultural experiences available.
Caves
Crete has hundreds of caves. Three are accessible as tourist sites:
- Dikteon Cave (Lasithi Plateau): mythological birthplace of Zeus, well lit, 250 steps down and back
- Sfendoni Cave (Zoniana village, Rethymno): stalactites and stalagmites, guided tours
- Melidoni Cave (Rethymno): historical significance (massacre site during Ottoman period), memorial chapel inside
Practical note
Rain in Crete often comes in fronts of 1-2 days, not weeks. Check the 3-day forecast and plan accordingly. Summer storms typically clear within hours.
Live weather: Crete Direct weather for all regions.