Plan a Summer Visit: July - September
The most popular season in the park offers the widest selection of activities and services.
Summer Guide and Itineraries
Warm daytime temperatures and cool evening temperatures. Sunny days dominate with occasional thunderstorms. Expect a 5° temperature decrease for every 1,000 foot increase in elevation. View the weather forecast for each area prior to your visit. Manzanita Lake Area (5,800 ft / 1,767 m) average summer high / low: 39° / 82°F ( 4° / 28°C).
Generally, all park areas and trails are accessible in the summer season. Heavy snowpack can delay opening of the park highway and Warner Valley and Juniper Lake Roads. Check the status of park roads prior to your visit, especially if planning a visit in July.
Snow can linger on park trails well into the summer months; view current trail conditions to help you prepare. Bumpass Hell Trail is often closed due to winter hazards into June or July. Snow patches can persist on the Lassen Peak Trail into August, however the trail is always open to over-the-snow travel. Hikers can take the Reach Higher Trail Challenge to earn a free commemorative bandana. A free permit is required for backpacking.
Summer offers the greatest selection of activities in the park. Summer-only activities include: summer ranger-led programs, most special events, field seminars, and the Highway ParkCaching (GPS) Challenge.
All facilities and services are open daily in the summer season (July through September); view operating hours. The park's eight campgrounds offer both first-come, first-served and reservable campsites. Campsites can fill up on holiday weekends and during special events. Additional campground are available outside the park in the surrounding Lassen National Forest.
Wildflower season extends from May to September. Wildflowers peak in high elevation areas between July and September. Many of the same species that bloom in May and June at lower elevations including Manzanita and Butte Lake will appear later in the Summit Lake and Lassen Peak areas.
Hazy or smoky conditions may occur during fall. This may be due to fires in the region or in the park. Lightning-caused fire occurs naturally in the Sierra Nevada. In some areas, the park may have prescribed fires to mimic natural fires to promote forest health and reduce the risk of larger fires.
Last updated: April 19, 2021