Climate averages 1991–2020
San Juan, Argentina weather
by month.
See how the year changes. January has the highest average daily maximum; June has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: MarchAprilMayAugustSeptemberOctoberNovember
Long-term climate patterns, not a forecast for a particular trip.
Across the year San Juan, Argentina averages a daytime high of 24.1°C and a nighttime low of 11.4°C, with about 192 mm of rain on roughly 36 days. January is the warmest month (average high 31.0°C) and July the coolest (16.4°C). March is the wettest month with 24 mm; June is the driest with 7.8 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): March, April, May, August, September, October and November. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in San Juan
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 Juan, Argentina climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 31.0°C19.2°C | 19.2°C | 17 | 3.2 | 13.914 h |
| February | 29.7°C18.0°C | 18.0°C | 20 | 3.4 | 13.213 h |
| March | 27.2°C15.8°C | 15.8°C | 24 | 3.9 | 12.312 h |
| April | 23.2°C11.6°C | 11.6°C | 18 | 3.3 | 11.311 h |
| May | 19.6°C7.6°C | 7.6°C | 10 | 2.6 | 10.511 h |
| June | 17.4°C4.1°C | 4.1°C | 7.8 | 2.0 | 10.110 h |
| July | 16.4°C2.9°C | 2.9°C | 8.2 | 2.2 | 10.310 h |
| August | 19.4°C5.0°C | 5.0°C | 10 | 2.3 | 11.011 h |
| September | 21.8°C8.0°C | 8.0°C | 17 | 3.3 | 11.912 h |
| October | 25.1°C11.8°C | 11.8°C | 21 | 3.5 | 12.813 h |
| November | 28.0°C15.0°C | 15.0°C | 16 | 3.2 | 13.714 h |
| December | 30.3°C17.7°C | 17.7°C | 22 | 3.3 | 14.214 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
Nearby cities
- RawsonArgentina · 5 kmHigh 23.7°C · Low 10.8°C · 192 mm rain a year
- MendozaArgentina · 153 kmHigh 20.6°C · Low 9.9°C · 453 mm rain a year
- San MartínArgentina · 172 kmHigh 23.3°C · Low 12.0°C · 278 mm rain a year
- ColinaChile · 274 kmHigh 22.7°C · Low 11.6°C · 639 mm rain a year
- OvalleChile · 275 kmHigh 25.0°C · Low 12.8°C · 151 mm rain a year
- San LuisArgentina · 284 kmHigh 23.0°C · Low 12.4°C · 665 mm rain a year
- PeñalolénChile · 286 kmHigh 19.9°C · Low 8.8°C · 683 mm rain a year
- QuilicuraChile · 289 kmHigh 21.6°C · Low 10.1°C · 639 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-3, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at -31.50°, -68.50° (5 km from the city centre), adjusted down by 0.2°C for the difference between the city's elevation (646 m) and the cell's (615 m). Rain comes from the 0.25° cell at -31.50°, -68.50°. Rawson lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.