Badajoz sits in one of the hottest parts of Spain. Summer afternoons regularly hit 40 °C and the city largely empties between two and six in the afternoon — even by Spanish standards, the siesta is taken seriously here. Outside the high summer, the climate is mild and dry.
Spring (March-May) is the best time. Days are warm but not punishing, the countryside is green, and the spring wildflowers across Extremadura are remarkable. Carnaval in February or early March is one of the largest in Spain — Badajoz takes its carnival very seriously, with a week of parades and elaborate competing comparsas.
Autumn (September-November) is also pleasant, with mild temperatures and the matanza pig-slaughter season getting underway across the surrounding villages — a good time for trying fresh chorizo and morcilla.
Summer (June-August) is hot enough to be an issue for sightseeing. Visit early morning or after 7pm; many shops close 2-6 in the afternoon. Winter (December-February) is mild and quiet, with cool dry days and crisp nights.
Two festivals worth timing for: the Festival Ibérico de Música in early June brings Spanish and Portuguese classical and folk musicians to the Alcazaba. The San Juan festival in late June fills the streets for nearly a week.