October and November are the best months — mild, dry, with the Cervantino festival in late October and early November filling the city with theatre, dance, and music. November also sees the city's distinctive Day of the Dead celebrations. February to May are warm and dry.
Summer rains (June to September) cool the city but bring afternoon downpours; the climate is generally mild year-round because of the altitude (around 2,000 m). The city's elevation can leave first-time visitors slightly breathless on the steep alleys for the first day or two.