Climate averages 1991–2020
San Martín weather
in December.
A hot, fairly dry month: the 2nd warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in San Martín: daytime highs average 30.9°C and nights cool to about 18.8°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 39 mm of rain on roughly 7 days, which makes December a fairly dry month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 17 min on an average December day.
The nearest other city in this atlas is Mendoza (41 km away). In December its highs average 27.6°C, 3.3°C cooler than San Martín, with 48 mm of rain.
Among the 67 cities listed in Argentina, San Martín ranks 4th of 67 for the warmest December highs and 8th of 67 for the driest December (rainfall, lowest first). The mean December high of those 67 cities is 27.9°C; San Martín is 3.0°C warmer than that mean.
From December to January, average highs rise by 0.4°C to 31.3°C, and monthly rainfall rises from 39 mm to 48 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
San Martín climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 31.3°C20.0°C | 20.0°C | 48 | 7.7 | 14.114 h |
| February | 29.7°C18.6°C | 18.6°C | 38 | 6.4 | 13.313 h |
| March | 26.7°C16.3°C | 16.3°C | 43 | 6.2 | 12.312 h |
| April | 22.0°C11.9°C | 11.9°C | 20 | 4.3 | 11.311 h |
| May | 17.8°C8.1°C | 8.1°C | 12 | 2.6 | 10.410 h |
| June | 14.9°C4.4°C | 4.4°C | 5.5 | 1.3 | 10.010 h |
| July | 14.5°C3.2°C | 3.2°C | 5.6 | 1.6 | 10.210 h |
| August | 17.7°C5.3°C | 5.3°C | 10 | 1.9 | 10.911 h |
| September | 21.1°C8.5°C | 8.5°C | 11 | 2.3 | 11.912 h |
| October | 24.9°C12.5°C | 12.5°C | 20 | 3.9 | 12.913 h |
| November | 28.4°C16.0°C | 16.0°C | 27 | 5.1 | 13.814 h |
| December, selected | 30.9°C18.8°C | 18.8°C | 39 | 6.7 | 14.314 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Mendoza in DecemberArgentina · 41 kmHigh 27.6°C · Low 16.3°C · 48 mm rain
- Rawson in DecemberArgentina · 167 kmHigh 29.8°C · Low 16.9°C · 22 mm rain
- San Rafael in DecemberArgentina · 171 kmHigh 29.3°C · Low 16.7°C · 53 mm rain
- San Juan, Argentina in DecemberArgentina · 172 kmHigh 30.3°C · Low 17.7°C · 22 mm rain
- Peñalolén in DecemberChile · 196 kmHigh 24.9°C · Low 13.6°C · 25 mm rain
- San Luis in DecemberArgentina · 201 kmHigh 28.9°C · Low 18.0°C · 101 mm rain
- Puente Alto in DecemberChile · 204 kmHigh 25.9°C · Low 13.2°C · 25 mm rain
- Colina in DecemberChile · 205 kmHigh 27.9°C · Low 16.3°C · 13 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for San Martín) is explained once on the San Martín year overview and on the Sources, method and limits page.