Last updated: June 24, 2025
In San Juan Capistrano, United States, the average temperature in September is a pleasant 21°C (70°F). Expect a minimum of 15°C (59°F) and a maximum of 33°C (91°F), making it an ideal time for outdoor activities. With only 3 mm (0.1 in) of precipitation over 0 days, you can look forward to mostly dry weather. The average humidity hovers around 68%, ensuring a comfortable atmosphere throughout the month.
In September in San Juan Capistrano, the average temperature is 21°C (70°F) with maximums reaching up to 33°C (91°F) and minimums dropping as low as 15°C (59°F). This pleasant climate makes San Juan Capistrano an ideal destination for outdoor adventures and exploration during your travels.
In San Juan Capistrano in September, the precipitation amount is 3 mm (0.1 in) during a total of 0 days.
In San Juan Capistrano in September humidity is 68%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace, making the air feel slightly heavy and sticky, which can be quite exhausting for travelers.
In San Juan Capistrano in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in San Juan Capistrano.
UV Risk Categories
Weather in San Juan Capistrano varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in San Juan Capistrano, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 14°C (58°F) | 60 mm (2.3 inches) | 74% | moderate |
| February Weather | 14°C (57°F) | 55 mm (2.2 inches) | 79% | high |
| March Weather | 14°C (58°F) | 54 mm (2.1 inches) | 75% | very high |
| April Weather | 16°C (61°F) | 25 mm (1.0 inches) | 70% | very high |
| May Weather | 16°C (62°F) | 14 mm (0.5 inches) | 70% | extreme |
| June Weather | 18°C (65°F) | 3 mm (0.1 inches) | 72% | extreme |
| July Weather | 21°C (70°F) | 3 mm (0.1 inches) | 73% | extreme |
| August Weather | 22°C (71°F) | 3 mm (0.1 inches) | 69% | very high |
| September Weather | 21°C (70°F) | 3 mm (0.1 inches) | 68% | very high |
| October Weather | 20°C (68°F) | 9 mm (0.4 inches) | 67% | high |
| November Weather | 17°C (63°F) | 22 mm (0.8 inches) | 68% | moderate |
| December Weather | 14°C (58°F) | 69 mm (2.7 inches) | 71% | moderate |