Monthly climate guide
San Luis weather in September
September in San Luis is typically warm, with average daytime highs around 22°C (72°F) and night-time lows near 7°C (45°F). The month usually brings about 21 mm of rain (fairly dry) and is a mix of sun and cloud. Daytime highs are 3°C warmer than August and 3°C cooler than October.
What stands out in September
- Expect a big gap between day and night — about 15°C.
- Seasonally, September counts as early spring in San Luis — the seasons are reversed south of the equator.
- It's one of the drier months, with about 61% less rain than San Luis's average.
- San Luis is usually about 2°C cooler than Córdoba, 290 km away, in September.
Avg high
22°C
72°F
Avg low
7°C
45°F
Rainfall
21 mm
fairly dry
Humidity
51%
relative
Sky
40%
cloud · a mix of sun and cloud
San Luis weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 32°C / 90°F | 18°C / 64°F | 100 mm | 50% | 41% |
| February | 30°C / 87°F | 17°C / 62°F | 124 mm | 57% | 43% |
| March | 28°C / 82°F | 14°C / 57°F | 72 mm | 59% | 37% |
| April | 24°C / 74°F | 11°C / 51°F | 65 mm | 66% | 46% |
| May | 19°C / 67°F | 7°C / 45°F | 19 mm | 71% | 55% |
| June | 16°C / 61°F | 4°C / 39°F | 8 mm | 67% | 41% |
| July | 16°C / 60°F | 3°C / 37°F | 5 mm | 64% | 44% |
| August | 19°C / 66°F | 5°C / 40°F | 8 mm | 55% | 39% |
| September | 22°C / 72°F | 7°C / 45°F | 21 mm | 51% | 40% |
| October | 25°C / 77°F | 10°C / 50°F | 57 mm | 51% | 45% |
| November | 29°C / 84°F | 14°C / 57°F | 101 mm | 49% | 40% |
| December | 32°C / 89°F | 16°C / 61°F | 70 mm | 46% | 37% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- An extra layer — evenings are noticeably cooler than afternoons
Is September a good time to visit San Luis?
Compare the months in the chart above to find your ideal window.
Best time to visit San Luis →Other Argentina cities in September
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San Luis weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/argentina/san-luis/september
<a href="https://weathercompare.eu/weather/argentina/san-luis/september">San Luis weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/argentina/san-luis" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="San Luis weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/argentina/san-luis/september">San Luis weather in September</a> – WeatherCompare</p>
San Luis in September: quick answers
Is September a good time to visit San Luis?
September is a reasonable time for San Luis: highs around 22°C and about 21 mm of rain, though not one of the three best months.
How warm is San Luis in September?
Average highs are about 22°C (72°F) and average lows about 7°C (45°F), based on 10 years of daily data.
Does it rain a lot in San Luis in September?
San Luis typically gets around 21 mm of rain in September — fairly dry.
Figures are long-term averages for the area around San Luis (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.