Lassen Volcanic National Park weather in September
September in Lassen Volcanic National Park: nice, a little rain, with clean air — one of the best months to visit.
#2 of 12 months in Lassen Volcanic National Park · #33 of 604 destinations to visit in September · comfort 92/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Lassen Volcanic National Park climate normals — September
| Daytime high | 21°C / 70°F | 😎 nice |
|---|---|---|
| Nighttime low | 8°C / 46°F | |
| Feels like (high) | 18°C / 64°F | |
| Rainfall | 47 mm / 1.9 in | 🌦 some rain |
| Rainy days | 5 days | |
| Humidity | 53% | 🍃 comfortable |
| Dew point | 2°C / 35°F | |
| Sunshine | 11.2 h/day | |
| Daylight | 12.5 h | |
| Wind | 14 km/h / 9 mph | |
| Snowfall | 1 cm / 0.4 in | |
| Air quality (US AQI) | 41 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Lassen Volcanic National Park?
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Lassen Volcanic National Park in September — FAQ
- Is September a good time to visit Lassen Volcanic National Park?
- September in Lassen Volcanic National Park: nice, a little rain, with clean air — one of the best months to visit. It ranks #2 of 12 months for Lassen Volcanic National Park on SeasonMap's comfort score (92/100).
- What is the weather like in Lassen Volcanic National Park in September?
- In September, Lassen Volcanic National Park averages a daily high of 21°C and a low of 7.9°C, with about 47.4 mm of rain over roughly 5.4 rainy days.
- What is the air quality in Lassen Volcanic National Park in September?
- Lassen Volcanic National Park has a mean US Air Quality Index of about 41 in September.
- Does it snow in Lassen Volcanic National Park in September?
- Lassen Volcanic National Park sees roughly 1 cm of snowfall in September.