Last updated: August 22, 2025
In September, the average temperature in San Luis, Argentina is a pleasant 15°C (59°F). However, temperatures can swing dramatically, with a minimum of -2°C (29°F) and a maximum reaching up to 34°C (94°F). Expect about 21 mm (0.8 in) of precipitation over 3 days, accompanied by an average humidity of 45%. Whether you're exploring the sights or enjoying the outdoors, be prepared for a range of weather conditions!
In September, in San Luis, the average temperature is 15°C (59°F). Maximums can reach 34°C (94°F), and minimums can drop as low as -2°C (29°F). Travelers should be prepared for a wide range of temperatures, making layering essential for a comfortable visit.
In San Luis in September, the precipitation amount is 21 mm (0.8 in) over a period of 3 days.
In San Luis in September, humidity is 45%. With an average temperature of 15°C (59°F), this humidity feels like a refreshing yet mild environment for traveling, allowing for comfortable exploration without the discomfort of heavy heat.
In San Luis in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in San Luis.
UV Risk Categories
Weather in San Luis varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in San Luis, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 24°C (75°F) | 92 mm (3.6 inches) | 40% | extreme |
| February Weather | 22°C (72°F) | 79 mm (3.1 inches) | 48% | extreme |
| March Weather | 20°C (69°F) | 60 mm (2.4 inches) | 53% | extreme |
| April Weather | 17°C (63°F) | 72 mm (2.8 inches) | 63% | very high |
| May Weather | 13°C (55°F) | 32 mm (1.2 inches) | 67% | moderate |
| June Weather | 9°C (49°F) | 13 mm (0.5 inches) | 61% | moderate |
| July Weather | 9°C (48°F) | 9 mm (0.4 inches) | 55% | moderate |
| August Weather | 12°C (54°F) | 4 mm (0.2 inches) | 48% | high |
| September Weather | 15°C (59°F) | 21 mm (0.8 inches) | 45% | very high |
| October Weather | 18°C (64°F) | 32 mm (1.2 inches) | 43% | extreme |
| November Weather | 21°C (70°F) | 71 mm (2.8 inches) | 45% | extreme |
| December Weather | 23°C (74°F) | 63 mm (2.5 inches) | 40% | extreme |