Oaxaca City in June

October through April gives you perfect weather — sunny days, cool nights, and minimal rain. December and January are peak season, so book early and expect crowds at major sites. The Guelaguetza festival in July brings incredible indigenous dance performances but also sweltering heat and higher prices. March hits the sweet spot with fewer tourists and comfortable temperatures. Avoid September and October for weather — it's the tail end of rainy season and humidity makes exploring miserable. Day of the Dead celebrations in November are spectacular but book accommodations months ahead. Here's the thing about Oaxaca weather: even in peak season, you'll need a light jacket for evenings at this altitude.