- Best time to visit Lassen Volcanic: June and August to October. The weather is at its most comfortable then, and crowds are lighter than at the peak.
- Busiest month: July, with about 106,704 visits in a typical recent year. That is 3.7 times as many as May.
- Quietest month: March (6,301 visits), when weather or closures keep most people away.
- Cold: average highs stay below 40°F in December.
- Wettest month: January, with 6.5 inches on average.
Bar height: visitors that month, compared with the busiest month. Temperatures: average daily high and low (°F); rain and snow: monthly averages. Best marks the months we suggest.
Month by month
| Month | Crowds | Visits (typical) | High / low (°F) | Precipitation | Snow |
|---|---|---|---|---|---|
| January | Very quiet | 7,321 | 41° / 22° | 6.5 in | n/a |
| February | Very quiet | 6,612 | 42° / 22° | 5.5 in | n/a |
| March | Very quiet | 6,301 | 46° / 24° | 6.4 in | n/a |
| April | Very quiet | 9,064 | 50° / 28° | 4.3 in | n/a |
| May | Quiet | 28,705 | 61° / 35° | 2.9 in | n/a |
| June ★ | Busy | 71,730 | 70° / 41° | 1.3 in | n/a |
| July | Busiest | 106,704 | 79° / 46° | 0.3 in | n/a |
| August ★ | Busiest | 89,217 | 78° / 45° | 0.3 in | n/a |
| September ★ | Moderate | 63,201 | 72° / 41° | 0.7 in | n/a |
| October ★ | Moderate | 43,715 | 59° / 33° | 2.7 in | n/a |
| November | Very quiet | 9,279 | 47° / 26° | 4.7 in | n/a |
| December | Very quiet | 7,026 | 40° / 22° | 6.5 in | n/a |
Weather figures are NOAA 1991 to 2020 climate normals for the Manzanita Lake station (5,750 feet above sea level), 1 miles from Loomis Museum. Higher parts of the park are colder and snowier. Visitor numbers are the median of 2022 to 2025 monthly recreation visits from the National Park Service.
By season
- Spring (March to May): 10% of the year’s visits; average highs 46° to 61°F.
- Summer (June to August): 60% of the year’s visits; average highs 70° to 79°F.
- Fall (September to November): 26% of the year’s visits; average highs 47° to 72°F.
- Winter (December to February): 5% of the year’s visits; average highs 40° to 42°F.
Weekends and holidays
Even in a quiet month, holiday weekends fill parking lots and campgrounds. The 2027 federal holidays to plan around:
- Martin Luther King Jr. Day: Monday, January 18
- Presidents Day: Monday, February 15
- Memorial Day: Monday, May 31
- Juneteenth: Saturday, June 19
- Independence Day: Sunday, July 4 (observed Monday, July 5)
- Labor Day: Monday, September 6
- Columbus Day and Indigenous Peoples Day: Monday, October 11
- Veterans Day: Thursday, November 11
- Thanksgiving: Thursday, November 25
Entrance is free for U.S. residents on the park service’s fee-free days. The last one in 2026 is Veterans Day, November 11; the 2027 dates had not been announced when we checked. Free days are often busier. See the crowd calendar for all 64 parks.
Weather, in the park service’s words
Weather at Lassen can vary dramatically throughout the year. Average January temperatures are a high of 40.4 °F (4.7 °C) and a low of 20.8 °F (-6.2 °C). Average July temperatures are a high of 88.4 °F and a low of 49.8 °F. Temperatures reach 90 °F or higher on an average of 36.9 days, and drop to 32 ° or lower on an average of 164 days days annually.
From the National Park Service (public domain).
Today at Lassen Volcanic
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Alerts: National Park Service, checked hourly. Forecast: National Weather Service, for Kohm Yah-mah-nee Visitor Center. Always confirm on the official park site before you set out.
Sources
- National Park Service visitor use statistics (IRMA): monthly recreation visits, 2022 to 2025
- NOAA NCEI U.S. Climate Normals, 1991 to 2020 (monthly)
- National Park Service Data API: weather overview (public domain)
Last checked 1 November 2026.