San Martín de los Andes weather in September
September in San Martín de los Andes: cold, rainy, with clean air — a good time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#4 of 12 months in San Martín de los Andes · #1010 of 1413 destinations to visit in September · comfort 67/100 (tier C)
- Days
- 10°C
- Nights
- 3°C
- Wet days
- 12
- Sun
- 9.7 h
- Humidity
- 81%
- Daylight
- 12 h

Traveller notes on San Martín de los Andes in September
Notes from nearby Pucón (110 km away)
San Martín de los Andes doesn't have its own notes for September yet — these are about Pucón, close enough to share the season.
Pucon-forum threads on end-of-September visits are direct conditions are genuinely impossible to predict, more likely to land cool and wet than warm and settled this early in spring. Posters recommend contacting local trek operators about current conditions rather than a generic forecast, outfits adjusting or pausing tours depending on the week. Regulars are consistent rain is possible any point in the Lake District, no genuinely dry stretch even in favorable months. Villarrica volcano remains visible on a clear day, worth building flexibility around, some catching dramatic views while others see nothing but cloud. Posters recommend the local thermal springs as a reliable fallback regardless of the sky. Regulars call September a real toss-up, workable for some activities but genuinely weather-dependent. The record: 13.3C days feeling like a raw 12C, 5.9C nights, an extraordinarily high 252mm across nearly 15 days, a notably high 8.2cm of fresh accumulation and 82 percent humidity.
Other months in San Martín de los Andes
Regulars are specific late June counts as a better bet than May if you actually want snow on the ground, with real snowfall episodes already landing by early-to-mid June and roughly 7 snow days typical for the month. Our row backs that cold, genuinely wet read, 7.2C reading as a freezing 4C, over 2.5C nights feeling -1C, with a substantial 207.1mm of precipitation across 16.6 days and 100.4cm of snowfall. Regulars are consistent this counts as the quieter lead-in to the July-August winter-holiday peak, shorter daylight hours and harsher weather but genuinely fewer crowds than the school-holiday rush that follows. The record: 5.9 hours of sun, humidity 88.3 percent and AQI 24.
July is high season at Chapelco and the month the Argentina forum names first, though it adds that August skis just as well for better rates. The risk sits earlier: regulars say planning a ski trip before late July or early August has been genuinely risky, and that from mid to late August you start getting spring conditions - so July is the narrow middle. The snow itself they describe as good but inclined to ice, with little powder, and the base higher than you might expect thanks to the cable car. The views over Lacar and the Lanin volcano are the compensation. The record: 6.7C days that feel like 4C, 1.7C nights, 102.4cm of snow, 15.2 precipitation days and 6.4 hours of sun.
Patagonia forum threads confirm February sits squarely in the Southern Hemisphere summer season here, and it's genuinely one of the busiest months as vacationers fill the town before things quiet down again outside peak season. San Martín de los Andes was described by regulars as generally having somewhat better, more settled weather than nearby Bariloche, with a lower chance of rain than in the surrounding months. The overall read from posters familiar with the area: this is prime lake-district hiking and outdoor season, worth booking ahead given how popular the window is.
Forum posters describe August as full winter in San Martín de los Andes, cold overall but with skiing just as good as July and often better hotel rates. Posters flag late snowfall as a real possibility even into August and September, a genuine bonus for skiers rather than a downside. Posters are consistent that on a clear, sunny winter day conditions are really nice for short walks, with the Seven Lakes circuit nearby offering plenty of scenic options between ski days. Posters generally recommend coming prepared for cold temperatures and unpredictable weather regardless of the forecast, while still rating August a viable, budget-friendlier alternative to peak-July skiing here.
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San Martín de los Andes climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in San Martín de los Andes in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Shoulder seasonschool holidays in 2 of the markets that fill it, an ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for San Martín de los Andes's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherSan Martín de los Andes's weather peaks June–August.
Best weatherFair weatherToughest weather
What's on in San Martín de los Andes in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Chapelco ski season
25 Jun – 30 Sep · usuallyThe hill is twenty minutes out of town and usually turns the lifts on at the start of July, holding until late September. Low snow years open the base only, and the town says so plainly.
- Season
Snow season
Ski seasonAbout 51 cm of snow falls in the month.
from the climate normals
Nearby, and something's on
Within 300 km of San Martín de los Andes — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is San Martín de los Andes?
San Martín de los Andes in September — FAQ
- Is September a good time to visit San Martín de los Andes?
- September in San Martín de los Andes: cold, rainy, with clean air — a good time to visit. It ranks #4 of 12 months for San Martín de los Andes on SeasonMap's comfort score (67/100).
- What is the weather like in San Martín de los Andes in September?
- In September, San Martín de los Andes averages a daily high of 9.9°C and a low of 3.1°C, with about 101.7 mm of rain over roughly 11.5 rainy days.
- What is the air quality in San Martín de los Andes in September?
- San Martín de los Andes has a mean US Air Quality Index of about 29 in September.
- Does it snow in San Martín de los Andes in September?
- San Martín de los Andes sees roughly 50.9 cm of snowfall in September.
Within 300 km: San Carlos de Bariloche's Ski season around 29 Jun – 4 Oct.