Santiago sits at 33.4°S latitude in Chile’s Central Valley at 520m elevation between the Andes Mountains to the east and the Chilean Coastal Range to the west. The city has a Mediterranean climate with hot, dry summers and cool, wet winters, receiving 342mm of rainfall annually with 80% falling May through August. Santiago averages 2,700 hours of sunshine per year. The city’s semi-arid basin traps air pollution, producing a visible smog layer during winter temperature inversions (May-August). This guide provides exact monthly data to plan your Santiago trip.
Santiago Weather by Month: Temperature, Rainfall, and Sunshine
January
High 30°C (86°F), Low 13°C (55°F), Rainfall 0mm, Humidity 58%, Sunshine 325 hours. January is Santiago’s hottest and driest month. Days are blazing under the Andean sun with 325 hours of sunshine. Afternoon temperatures reach 30°C regularly, occasionally spiking to 35°C (95°F). Evening temperatures drop sharply to 13°C due to the altitude. Pack sunscreen, a hat, and a light jacket for evenings. The city empties as Santiaguinos head to the coast (Vina del Mar, 90 minutes by bus).
February
High 29°C (84°F), Low 13°C (55°F), Rainfall 2mm, Humidity 60%, Sunshine 295 hours. February is nearly as hot and dry as January. A few millimetres of rain might fall but statistically it is still a dry month. The city remains quiet as summer holidays continue through the month. February is the peak month for visiting nearby Cajon del Maipo and the Andes foothills.
March
High 28°C (82°F), Low 11°C (52°F), Rainfall 5mm, Humidity 62%, Sunshine 270 hours. March brings the first hint of autumn. Daytime temperatures ease to 28°C and evenings cool noticeably. Rainfall remains negligible. This is one of Santiago’s best months: warm without the January intensity, with clear skies and the city returning to life after summer holidays. Grape harvest season in the Maipo and Casablanca wine valleys.
April
High 24°C (75°F), Low 8°C (46°F), Rainfall 15mm, Humidity 65%, Sunshine 210 hours. April brings true autumn. Days are pleasant at 24°C but nights drop to 8°C. The first real rain arrives. The Andes receive their first snow, visible as a white cap on the eastern skyline. A beautiful month for walking Barrio Lastarria and Bellavista.
May
High 19°C (66°F), Low 6°C (43°F), Rainfall 60mm over 5 days, Humidity 72%, Sunshine 160 hours. May is the start of Santiago’s wet season. Rainfall jumps to 60mm and sunshine drops to 160 hours. The temperature inversion begins, trapping smog over the city. Days are cool at 19°C and nights cold at 6°C. Pack warm layers. Ski resorts in the Andes begin receiving significant snow.
June
High 16°C (61°F), Low 4°C (39°F), Rainfall 85mm over 7 days, Humidity 78%, Sunshine 120 hours. June is the wettest month at 85mm across 7 days. Daytime struggles to reach 16°C, nights drop to 4°C. The smog layer is at its worst. Ski resorts (Valle Nevado, La Parva, El Colorado) open by mid-month. The city feels grey and damp. Lowest sunshine of the year at 120 hours.
July
High 15°C (59°F), Low 3°C (37°F), Rainfall 80mm over 7 days, Humidity 80%, Sunshine 135 hours. July is the coldest month with nighttime lows of 3°C. Rainfall is still heavy at 80mm. Snow dusts the surrounding hills occasionally (once or twice per winter within the city). Ski season peaks. Central heating is common in hotels but not in budget accommodations. Pack a heavy jacket.
August
High 17°C (63°F), Low 5°C (41°F), Rainfall 55mm over 5 days, Humidity 76%, Sunshine 165 hours. August is the last wet month. Temperatures begin to climb, rain decreases, and sunshine hours increase. The smog starts to clear. Ski resorts remain open through late August or early September. A transitional month with unpredictable weather.
September
High 20°C (68°F), Low 7°C (45°F), Rainfall 30mm over 3 days, Humidity 70%, Sunshine 200 hours. September is spring and one of Santiago’s best months. Days warm to 20°C, rain drops to 30mm, and the smog clears as the inversion breaks. The Andes snowpack is still thick, creating dramatic views. Fiestas Patrias (Independence Day, September 18-19) fills the city with parades, rodeos, and food stalls.
October
High 23°C (73°F), Low 9°C (48°F), Rainfall 15mm over 2 days, Humidity 63%, Sunshine 250 hours. October delivers warm days, cool nights, minimal rain, and jacaranda trees in bloom across Providencia and Las Condes. The Andes snowpack begins melting. A near-perfect month for sightseeing. Book ahead as this is a popular season.
November
High 26°C (79°F), Low 11°C (52°F), Rainfall 8mm, Humidity 58%, Sunshine 285 hours. November is warm and dry, approaching summer conditions. Temperatures reach 26°C and rain is rare. The city is green from spring growth. The Andes still hold snow above 3,000m but the lower slopes are clear. Excellent month for outdoor dining and rooftop bars.
December
High 29°C (84°F), Low 12°C (54°F), Rainfall 2mm, Humidity 55%, Sunshine 310 hours. December is nearly summer. Temperatures approach 29°C and rain effectively stops. The city empties as summer holidays begin mid-month. Christmas decorations appear in malls and parks. Hot days with cool evenings remain the pattern.
Santiago Climate Data at a Glance
| Month | High (°C) | High (°F) | Low (°C) | Low (°F) | Rain (mm) | Rain Days | Sun (hrs) |
|---|---|---|---|---|---|---|---|
| Jan | 30 | 86 | 13 | 55 | 0 | 0 | 325 |
| Feb | 29 | 84 | 13 | 55 | 2 | 0 | 295 |
| Mar | 28 | 82 | 11 | 52 | 5 | 1 | 270 |
| Apr | 24 | 75 | 8 | 46 | 15 | 2 | 210 |
| May | 19 | 66 | 6 | 43 | 60 | 5 | 160 |
| Jun | 16 | 61 | 4 | 39 | 85 | 7 | 120 |
| Jul | 15 | 59 | 3 | 37 | 80 | 7 | 135 |
| Aug | 17 | 63 | 5 | 41 | 55 | 5 | 165 |
| Sep | 20 | 68 | 7 | 45 | 30 | 3 | 200 |
| Oct | 23 | 73 | 9 | 48 | 15 | 2 | 250 |
| Nov | 26 | 79 | 11 | 52 | 8 | 1 | 285 |
| Dec | 29 | 84 | 12 | 54 | 2 | 0 | 310 |
Santiago Weather Patterns and What to Expect
Santiago’s Mediterranean climate produces hot, bone-dry summers (December-March) with 28-30°C highs and virtually zero rainfall. Winter (June-August) brings 15-17°C days, 3-5°C nights, and 80% of annual rainfall. The transitional seasons (spring: September-November, autumn: April-May) offer the most comfortable weather for sightseeing with 19-26°C days and low to moderate rain.
Santiago’s biggest weather concern is air quality. The city sits in a basin between two mountain ranges, and during winter (May-August) a thermal inversion traps vehicle and industrial emissions over the city. PM2.5 levels regularly exceed safe limits. On “pre-emergency” days (declared by the government), 40% of vehicles are banned from the roads and outdoor exercise is discouraged. Check the Chilean Environment Ministry’s air quality index before outdoor activities in winter.
The 520m elevation means UV levels are higher than at sea level and evenings cool rapidly even after hot days. The 13°C overnight low in January surprises visitors who packed only for 30°C days. Always carry a jacket or sweater for evenings, year-round.
