The climate in southern California features seemingly endless days of sunshine and warm, dry nights, with occasional bouts of winter flooding. Coastal mornings can be hazy or overcast, especially in May and June. In San Francisco it can be chilly all year, and fog rolls in to spoil many a sunny day, though you can expect extreme variations in the Bay Area as a whole (you’ll soon see why the locals talk about “microclimates” around here). Much more so than in the south, winter in northern California can bring rain for weeks on end. Most hiking trails in the mountains are blocked between October and June by the snow that keeps California’s ski slopes among the busiest in the nation.