Last updated: June 18, 2025
In September, the average temperature in Sion, Canada hovers around 13°C (57°F). Be prepared for a range of temperatures, as it can drop to a chilly -1°C (31°F) or rise to a warm 32°C (90°F). During this month, expect 45 mm (1.8 in) of precipitation spread over 7 days, with an average humidity of 74%. Whether you’re basking in the warmth or bundled up against the cold, it's a month full of surprises!
In September in Sion, the average temperature is 13°C (57°F). The maximum can reach 32°C (90°F), and the minimum can be as low as -1°C (31°F). Be prepared for a wide range of temperatures when traveling during this time.
In Sion in September, the precipitation amount is 45 mm (1.8 in) spread over a duration of 7 days.
In Sion in September humidity is 74%. With an average temperature of 13°C (57°F), this humidity feels like a blanket of moisture wrapping around you, making outdoor excursions less comfortable and adding a stickiness to the air that could quickly fatigue travelers.
In Sion in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Sion.
UV Risk Categories
Weather in Sion varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sion, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (24°F) | 74 mm (2.9 inches) | 90% | low |
| February Weather | -5°C (24°F) | 59 mm (2.3 inches) | 91% | moderate |
| March Weather | 1°C (34°F) | 68 mm (2.7 inches) | 89% | moderate |
| April Weather | 5°C (42°F) | 69 mm (2.7 inches) | 85% | high |
| May Weather | 12°C (53°F) | 66 mm (2.6 inches) | 82% | very high |
| June Weather | 16°C (61°F) | 45 mm (1.8 inches) | 81% | very high |
| July Weather | 20°C (69°F) | 13 mm (0.5 inches) | 84% | very high |
| August Weather | 20°C (68°F) | 18 mm (0.7 inches) | 75% | very high |
| September Weather | 13°C (57°F) | 45 mm (1.8 inches) | 74% | high |
| October Weather | 5°C (42°F) | 59 mm (2.3 inches) | 85% | moderate |
| November Weather | 0°C (33°F) | 71 mm (2.8 inches) | 88% | low |
| December Weather | -4°C (26°F) | 72 mm (2.8 inches) | 93% | low |