Eugene's climate is classic western Oregon: wet, cool winters and dry, warm summers. Rain falls between November and April — not torrential but persistent, and the valley fog can sit for days. July, August, and September are the dry months, with daytime highs in the 25–30°C (75–85°F) range and very little rain.
Late May to early October is the comfortable window. The Oregon Country Fair in nearby Veneta, second weekend of July, is a regional institution. The Prefontaine Classic at Hayward Field, late May or early June, is the running event of the year. Football Saturdays in autumn turn the city green and yellow and book up the hotels — avoid or commit accordingly.