Last updated: March 2, 2024
The weather in San Isidro, Puerto Rico, during September is characterized by an average temperature of 28°C (82°F). Highs can soar to 32°C (89°F), while lows may dip to 25°C (77°F). Typically, the humidity level in San Isidro throughout September hovers around 79%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, San Isidro averages 173 mm (6.8 inches) of rainfall, typically over the course of 23 rainy days. The month enjoys an average of 12 hours 12 minutes of daylight, with the sun shining for approximately 10 hours 26 minutes each day. Additionally, there is a 48% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In September, the UV Index in San Isidro reaches a maximum of 13, indicating a level of Extreme exposure. The most intense UV radiation typically occurs between 12:00 and 14:00, during which unprotected skin may burn in as little as 10 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 | 1 | 2 | 5 | 9 | 12 | 13 | 13 | 10 | 7 | 4 | 1 | 1 | 0 |
| Exposure | Low | Moderate | VeryHigh | Extreme | VeryHigh | High | Moderate | Low | |||||
| Time to burn | 45 min | 30 min | 15 min | 10 min | 15 min | 25 min | 30 min | 45 min | |||||