The Westfjords have a narrow window of genuinely good visiting weather. Mid-June through August offers the most reliable conditions and nearly permanent daylight — the sun doesn't fully set at this latitude in midsummer, giving long evening light for photography and driving. The puffin colonies at Látrabjarg are at their most active in June and July; Hornstrandir boat trips run June through mid-August.
September sees the first autumn colours and fewer visitors, but weather becomes unpredictable and some mountain roads close early. Winter travel is possible but demanding — many roads are closed or impassable, ferry services reduce, and conditions can be severe. The compensations are northern lights on clear nights and a level of solitude that summer can't match. Come from mid-June to late July for the best combination of accessible roads, active wildlife, and light.