Last updated: March 2, 2024
The weather in San Marcos, United States, during September is characterized by an average temperature of 26°C (79°F). Highs can soar to 36°C (98°F), while lows may dip to 15°C (59°F). Typically, the humidity level in San Marcos throughout September hovers around 65%.
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Average temperature
Maximum temperature
Humidity
In September, San Marcos averages 112 mm (4.4 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 12 hours 17 minutes of daylight, with the sun shining for approximately 9 hours 13 minutes each day. Additionally, there is a 59% probability of sunny days during this period.
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Chance of sun
In September, the UV Index in San Marcos reaches a maximum of 11, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 15 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 0 | 1 | 2 | 4 | 7 | 9 | 10 | 10 | 9 | 6 | 3 | 2 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | High | Moderate | Low | ||||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 25 min | 30 min | 45 min | ||||||