Sucre's altitude (around 2,750 metres) gives it an exceptionally pleasant climate by Bolivian standards: warm sunny days and cool nights, with temperatures rarely much above 25°C even in summer or below freezing in winter. The city has been called the place with the best climate in Bolivia and it is hard to argue.
The dry season runs from May to October — these are the clearest months, with cold nights but brilliant blue days. The wet season from November to March brings afternoon thunderstorms but also greenery in the surrounding hills; mornings are usually fine. Avoid late January and February if you have problems with rain, since the heaviest downpours and the muddiest roads come then.
The biggest festival is Virgen de Guadalupe in early September, when processions and dances fill the streets. Independence Day (6 August) and the Fiesta de la Independencia in late May also draw crowds. The Tarabuco Sunday market is busiest year-round but particularly atmospheric in March during the Pujllay festival.