Viña del Mar weather in December

December is summer here and the board describes it as one long dry day with a cold end: around 30C in the afternoon, low twenties by ten at night, cooler again before dawn. Our row is that swing written as two numbers, 30C over 11.6C - an eighteen-degree range inside a single date. At 53.6 percent humidity the heat is dry, so a step into the shade cools you immediately, but the sun is strong enough that finding shade is the whole trick. Rain is 6.5mm across not quite one day. Most evenings want a sweater, and hotels are air conditioned where apartments often are not. The smog the board argues about belongs to winter: AQI 75 here against 138 in July. The record: 13.1 hours of sun.

Chile's forum notes that central Chile's rainy season runs through July and August, and Viña del Mar's coastal position keeps it milder than inland Santiago at the same time - forum posters compared Santiago's winter days landing in the 50s-70s F range, with the coast running a touch cooler but gentler overall. Rain here tends to arrive as occasional, fairly wet systems rather than a daily drizzle, matching the destination's real pattern of infrequent but noticeable rain days. Air quality is also consistently better on the coast than in the Santiago basin, a plus for anyone sensitive to smog.

Forum posters describe February as reliably nice and sunny, squarely inside Chile's summer and the peak of the city's tourist season, drawing huge crowds. The key caveat posters repeat consistently: the cold Humboldt Current keeps sea temperatures genuinely frigid even at the height of summer, commonly cited around 60F - a swim here is a much colder proposition than the sunny beach weather suggests. February also brings the well-known Vina del Mar International Song Festival (a major cultural event held in the city), adding to the crowds and energy but also meaning accommodation books up and prices rise accordingly during the festival dates.