🌤 Weather at Trione-Annadel State Park by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 42–74 °F | 51–83 °F | 42–84 °F | 38–64 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Santa Rosa, 4 mi away, elevation 166 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
Trione-Annadel State Park is a public state park in California near Santa Rosa in Sonoma County. Spanning 5,092 acres and established in 1971, this park offers a peaceful retreat into nature for visitors of all ages.
Quick Facts
| State | California |
| Nearest City | Santa Rosa |
| County | Sonoma |
| Park Size | 5,092 acres |
| Established | 1971 |
| Google Rating | ⭐ 4.6/5 (550 reviews) |
| Accessibility | Yes. See parks.ca.gov website for specific accessibility details. |
Location & Getting There
Trione-Annadel State Park is located near Santa Rosa, California. The park’s coordinates are 38.4522, -122.6346.
Things to Do
California state parks span an extraordinary range of landscapes — from ancient redwood forests and rugged Pacific coastline to Mojave Desert dunes and Sierra Nevada alpine meadows. Depending on the park, visitors can enjoy hiking through old-growth groves, swimming and surfing along miles of wild beaches, camping beneath towering sequoias, kayaking coastal sea caves, mountain biking oak-studded foothills, fishing in alpine lakes, rock climbing granite formations, and wildlife watching for everything from elephant seals to California condors. Many parks also preserve important cultural and historic sites, including Native American heritage areas, Gold Rush-era settlements, and Spanish mission ruins.
Best Time to Visit
California’s parks are a year-round destination, though the ideal season depends on the region. Coastal parks enjoy mild weather from spring through fall, with summer fog keeping temperatures comfortable along the central and northern coast. Desert parks like Anza-Borrego are best visited October through April — summer temperatures can exceed 110°F. Mountain parks in the Sierra Nevada are most accessible June through October, when snow melts and trails open. Spring (March–May) brings wildflower super blooms in the southern deserts. Fall offers warm days, thinner crowds statewide, and stunning foliage at higher elevations. Winter is the quiet season at most parks and brings excellent whale watching along the coast.
Visitor Tips
Most California state parks charge a day-use parking fee of $10 per vehicle: purchasing an annual pass ($125) is highly recommended if you plan to visit multiple parks. Camping reservations can be made through ReserveCalifornia up to 6 months in advance — popular coastal campgrounds book within minutes of opening. Cell service is limited or nonexistent in many parks, so download maps and directions before you leave. Bring layers: California’s microclimates can shift dramatically even within a single park. Dogs are generally allowed in campgrounds and on paved roads but not on most trails or beaches in state parks.
Explore More California State Parks
Trione-Annadel State Park is one of many outstanding state parks in California. Discover more parks in our Best State Parks in California guide, or use our Park Finder to search by activity, location, or features.
Nearby state parks: If you have extra time, Annadel State Park is a short drive away, and Sugarloaf Ridge State Park is a short drive away.
🐾 Dogs & Pets at Trione-Annadel State Park
- Pets allowed? statewide rule
- Dogs are permitted in California State Parks only in developed areas — campgrounds, picnic areas, parking lots and paved roads — and are prohibited on most trails, beaches and undeveloped areas unless specifically designated as dog-friendly.
- Leash rule statewide rule
- Maximum 6-foot leash at all times; dogs may not be left unattended.
- Beaches & swim areas statewide rule
- Dogs are prohibited on most state beaches; only beaches specifically designated as dog-allowed permit them (varies by park).
- Cabins & lodging statewide rule
- Pets are generally not allowed in buildings or cabins; overnight campers must keep dogs inside a tent or vehicle at night.
- Statewide exceptions statewide rule
- Designated dog-friendly trails and beaches vary park by park; misrepresenting a pet as a service animal is a misdemeanor.
Are dogs allowed at Trione-Annadel State Park?
Dogs are permitted in California State Parks only in developed areas — campgrounds, picnic areas, parking lots and paved roads — and are prohibited on most trails, beaches and undeveloped areas unless specifically designated as dog-friendly. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via parks.ca.gov. More: California state parks guide · Dog rules in all 50 states compared
Park Location
Plan your gear for Trione-Annadel State Park
From our editorial guides, matched to this park’s activities:
