La Paz in January

May through September is your sweet spot — dry season means clear skies and those postcard views of snow-capped Illimani. July gets crowded with European backpackers escaping their summer, but the weather is perfect. December through March brings rain that turns the city's red dirt roads into muddy nightmares. Here's the thing about altitude: your first two days will be rough regardless of when you visit. Bring coca leaves or pills, drink water constantly, and don't plan anything strenuous until day three.