Puebla sits at 2,100 metres above sea level, which keeps temperatures mild year-round. Days are typically warm and sunny (18–25°C); evenings can be cool even in summer. The altitude also means you may feel breathless for the first day or two if coming from sea level.
March–May is generally the most pleasant period: warm, dry, and culminating in Cinco de Mayo festivities (5 May), when Puebla commemorates its 1862 defeat of the French army with parades, reenactments, and crowds that fill the Zócalo for days.
August–October is the season for chiles en nogada — the walnut-cream-and-pomegranate dish that appears on menus only when fresh walnuts and pomegranates are available. If you want to eat the dish at its best, plan your visit for September, when both ingredients are perfectly ripe. September also brings Mexican Independence Day (16 September) celebrations.
Semana Santa (Holy Week, March or April) brings elaborate religious processions through the historic centre: Puebla's strong Catholic tradition makes these among the most atmospheric in Mexico.
January is the quietest month: grey skies, occasional drizzle, thin crowds. Good for museum time; not ideal for outdoor exploration.
The rainy season runs June–September, with afternoon thunderstorms that are usually brief and clear by evening.