Unlike southern Spain, which can become uncomfortably hot between June and September, Asturias is actually at its best during these months. Temperatures are typically in the high twenties celsius on the coast, or a few degrees cooler in the hills, with plenty of sun interspersed with sporadic rain showers. It's significantly warmer and sunnier than the UK.
Snow falls, and remains on high ground, between November and April. Asturias boasts 3 ski stations, whose most reliable months are January to March. If you're into wild flowers or river kayaking, April-June is the best period. Many towns and villages host their own Feria de Abril in April; some have music or art festivals in July or August (Gijon and Aviles in particular); while some smaller mountain villages stage hazelnut festivals in October.
NB, please do not rely solely on this information for your travel planning.
ASTURIAS: BY AIR
From the UK: carriers include easyJet, Vueling and Iberia.
Within Europe: try Air Europa, Iberia, Volotea and Vueling.
By boat from the UK: Brittany Ferries sails from Plymouth or Portsmouth to Santander; journey time is about 24 hours.
If you don't want to hire a car, the narrow-gauge Feve railway winds its way slowly but scenically across northern Spain, connecting all the main towns and some smaller villages on its 1,100km journey from Bilbao to Ferrol in Galicia. Once in Oviedo, normal Renfe trains link the triangle of Gijón, Avilés and Oviedo as well as stops in between. See Seat 61 for more detail.