Last updated: August 27, 2025
In September, the average temperature in San Antonio, Peru hovers around 6°C (43°F). Expect chilly nights with a minimum of -7°C (20°F), while daytime highs can reach up to a pleasant 16°C (62°F). Precipitation can be expected, with about 78 mm (3.1 in) of rain spread over 21 days. Humidity remains moderate at about 53%, adding to the atmosphere of this captivating destination.
In September in San Antonio, the average temperature is 6°C (43°F). Maximums can reach 16°C (62°F) and minimums can be as low as -7°C (20°F). Travelers should be prepared for a mix of chilly and mild weather, so layering is essential.
In San Antonio in September, the precipitation amount is 78 mm (3.1 in) distributed over 21 days.
In San Antonio in September, humidity is 53%. With an average temperature of 6°C (43°F), this humidity feels like a crisp, invigorating chill that can make exploring outdoors refreshing yet slightly uncomfortable, requiring warm layers and occasional breaks to warm up.
In San Antonio in September, the maximum UV index reaches an alarming 17, which falls under the extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to stay protected. For more details on the hourly UV index in San Antonio, you can check Hourly UV Index in San Antonio.
UV Risk Categories
Weather in San Antonio varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in San Antonio, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 6°C (43°F) | 250 mm (9.8 inches) | 89% | extreme |
| February Weather | 6°C (43°F) | 297 mm (11.7 inches) | 90% | extreme |
| March Weather | 6°C (43°F) | 274 mm (10.8 inches) | 90% | extreme |
| April Weather | 6°C (42°F) | 126 mm (5.0 inches) | 90% | extreme |
| May Weather | 5°C (41°F) | 46 mm (1.8 inches) | 84% | extreme |
| June Weather | 4°C (40°F) | 13 mm (0.5 inches) | 67% | extreme |
| July Weather | 4°C (40°F) | 15 mm (0.6 inches) | 53% | extreme |
| August Weather | 5°C (41°F) | 23 mm (0.9 inches) | 47% | extreme |
| September Weather | 6°C (43°F) | 78 mm (3.1 inches) | 53% | extreme |
| October Weather | 6°C (43°F) | 153 mm (6.0 inches) | 67% | extreme |
| November Weather | 7°C (44°F) | 185 mm (7.3 inches) | 75% | extreme |
| December Weather | 6°C (44°F) | 252 mm (9.9 inches) | 82% | extreme |