Last updated: August 27, 2025
In September, the average temperature in Castel San Pietro, Switzerland hovers around 19°C (66°F). Expect a range from a cool 8°C (46°F) to a warm 29°C (84°F). The area experiences about 146 mm (5.8 in) of precipitation spread over 11 days, contributing to an average humidity of 74%.
In September in Castel San Pietro, the average temperature is 19°C (66°F). Maximum temperatures can reach 29°C (84°F), while minimums can drop as low as 8°C (46°F). This makes Castel San Pietro an ideal destination for travelers seeking comfortable weather and a mix of warm and cool days.
In Castel San Pietro in September, the total precipitation amount is 146 mm (5.8 in) recorded over a span of 11 days.
In Castel San Pietro in September humidity is 74%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it ideal for leisurely outdoor exploration but potentially heavy for those not accustomed to tropical conditions.
In Castel San Pietro in September, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Castel San Pietro, you can refer to this Hourly UV Index in Castel San Pietro.
UV Risk Categories
Weather in Castel San Pietro varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Castel San Pietro, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 4°C (39°F) | 42 mm (1.7 inches) | 88% | low |
| February Weather | 6°C (43°F) | 46 mm (1.8 inches) | 81% | moderate |
| March Weather | 9°C (48°F) | 88 mm (3.5 inches) | 76% | moderate |
| April Weather | 13°C (56°F) | 124 mm (4.9 inches) | 77% | high |
| May Weather | 17°C (63°F) | 143 mm (5.6 inches) | 74% | very high |
| June Weather | 22°C (72°F) | 161 mm (6.4 inches) | 71% | very high |
| July Weather | 24°C (75°F) | 164 mm (6.5 inches) | 67% | very high |
| August Weather | 24°C (75°F) | 136 mm (5.3 inches) | 64% | very high |
| September Weather | 19°C (66°F) | 146 mm (5.8 inches) | 74% | high |
| October Weather | 14°C (58°F) | 152 mm (6.0 inches) | 87% | moderate |
| November Weather | 9°C (49°F) | 169 mm (6.7 inches) | 88% | moderate |
| December Weather | 5°C (41°F) | 94 mm (3.7 inches) | 85% | low |