Potosí weather in May

Uyuni's forum is clear that by May the famous mirror effect on the salt flats is no longer reliable - that's really a December-through-March phenomenon, and much of the salar has dried out by this point, though a lucky visitor might still catch some water in patches. A rain jacket becomes unnecessary this time of year, but nights turn genuinely brutal - one traveler reported around -10C at 4,400m elevation. The honest framing from regulars: come for the dry, otherworldly salt-flat scenery and star-filled skies, not for a shot at the reflection photos, and pack serious cold-weather gear regardless of how warm the days feel.

Forum posters describe Bolivia's rainy season as running roughly late December through March, with March still solidly within it though conditions improve noticeably as April approaches. Posters specifically discussing the Altiplano, where Potosí sits, note rain here usually isn't a major problem for city-based travel, though it's still wise to build in a few spare days for potential delays. Posters describe the typical pattern as heavy afternoon rain for a few hours rather than an all-day event, with rains generally easing toward the end of March. Posters do caution that March isn't ideal for trekking or mountain excursions specifically, since peaks are often shrouded in cloud this time of year. Posters generally rate March as still rainy but genuinely improving for Potosí, city sightseeing more reliable than mountain-based activities.

Forum posters place September within Bolivia's dry season (roughly May-September) and its spring shoulder (September-November) - genuinely one of the better windows, with plenty of sunshine and very little rain across the Altiplano and salt flats. The clear tradeoff, though, is night cold: even with excellent, continuously clear daytime skies, nighttime temperatures on the high plain drop sharply, and posters say a proper sleeping bag or well-insulated accommodation is essential rather than optional. One seasonal caveat specific to this time of year: farmers burning cleared land in August-September can create haze that dulls the views on some days.