Summer (June to August) is the prime season, and for good reason. Days are very long — around the solstice, darkness barely falls at all. The weather is as stable as it gets (which is not saying much — the Faroes are notoriously changeable). Puffins are on Mykines from late April to August; the first week of August sees Ólavsøka, the national holiday, which draws Faroese from all over the islands to Tórshavn for rowing races, concerts, and chain dancing in the streets. The G! music festival on Eysturoy takes place in mid-July.
The downside of summer: the Faroes have become a popular destination, and popular spots like Gásadalur and Mykines can feel crowded on fine days. Accommodation should be booked well in advance.
Spring and autumn offer quieter visits. May and September can be beautiful — the light is extraordinary, the green hills are at their most vivid in May, and you are unlikely to share a mountain trail with many others. Bird migration peaks in spring and autumn. Weather is more unpredictable, and some tourist services run reduced schedules.
Winter (November to February) is for the committed. Days can be as short as five hours, storms are frequent, and ferry services to smaller islands may be disrupted for days at a time. But the Faroes are hauntingly beautiful in winter light, and a clear evening can bring a dramatic aurora over the harbours. If you can handle the dark and the cold, you will have the islands essentially to yourself.
The average summer temperature is around 13°C; winter averages around 3°C. It is never extremely hot or extremely cold — the Gulf Stream keeps the climate milder than the latitude suggests.