Muir Woods Weather: What to Expect Year-Round
Muir Woods sits inside a coastal redwood forest on the western slope of Mount Tamalpais, about 17 miles from downtown San Francisco. The weather here is cooler, damper, and foggier than the surrounding Bay Area. That microclimate is exactly what keeps the old-growth redwoods alive.
Here is what the forest actually feels like, month by month, and what to pack so you are comfortable once you step beneath the canopy.
Temperature Range
According to the National Park Service, temperatures in the monument generally range from 40°F to 70°F (4°C to 21°C) across the year. The canopy traps cool, moist air close to the forest floor, so it can easily feel 10 to 20 degrees cooler inside Muir Woods than on the bridge, in Sausalito, or across the bay in San Francisco.
Bring a jacket or a warm layer every single visit, even when it is 85°F in the city.
The Rain Season: Late October Through Early May
The NPS describes the wet season as running from late October to early May. Winter storms can be heavy, and the creek that runs through the valley swells during and after rainfall. Trails can be muddy; the main paved loop stays passable in all but the biggest storms.
Winter visits reward anyone willing to bring rain gear. The forest smells of wet duff and bay laurel, the creek runs loud, and crowds thin out considerably.
Summer: Cool, Dry, and Foggy
Summer (June through August) is the driest stretch of the year, but it is not hot in the forest. The Pacific pushes marine fog inland most summer mornings. Expect thick fog early, burning off by early afternoon.
That fog isn’t just atmosphere. Coast redwoods capture moisture directly from fog through their needles and through fog drip onto the forest floor, supplementing rainfall during the dry summer months. It’s a big reason these trees grow here and not 50 miles inland.
Fall Is the Best Weather
Many locals and the park service agree: late summer through fall (August to October) is the most pleasant stretch of weather at Muir Woods. Fog thins, skies clear earlier in the day, and temperatures sit comfortably in the 60s. If you want warm afternoons and green redwoods without winter rain, aim for September or October.
Monthly Snapshot
- January to March: Coolest months. Regular rain. Average highs mid-50s, lows around 40°F. Creek runs full.
- April to May: Rain tapers off. Wildflowers emerge in the surrounding hills. Cool mornings, mild afternoons.
- June to August: Dry season. Heavy morning fog. Afternoons in the 60s to low 70s inside the forest.
- September to October: Clearest, warmest, most reliable weather of the year.
- November to December: Rain season begins. Cool and often wet. Fewer visitors.
What to Wear & Pack
The forest is cool and damp year-round. Dress for the forest, not the forecast.
Every visit
- Base layer + insulating mid-layer + outer shell. Layering works in every season because conditions can swing 15°F between the parking lot and the deepest shade at Cathedral Grove.
- Closed-toe walking shoes or light hiking boots. The main loop is paved, but side trails have exposed roots and can be slick from fog drip and damp duff.
- At least 1 liter of water per person, plus a snack. The cafe by the visitor center sells drinks and light food, but there’s no water or food on the trails themselves.
- Download your reservation pass, maps, and directions before leaving the city — no cell service in the canyon.
- A camera or phone for photos. Low light under the canopy makes a smartphone’s night mode and a steady hand helpful.
Seasonal packing notes
- Spring (March–May): Trails can still be wet. Waterproof shoes and a light rain jacket are worth packing.
- Summer (June–August): Counterintuitively, layers matter most in summer. Forest temps stay in the 60s even when SF is in the 80s. A fleece or hoodie under a light shell handles the morning fog.
- Fall (September–November): The most forgiving weather. A single mid-weight layer usually works.
- Winter (December–February): Waterproof rain jacket is non-negotiable. Traction on shoes matters — boardwalks and bridges get slippery after rain.
What not to bring
- Pets. Not allowed on any trail. Service animals (ADA-defined) are the exception. See the Pet Policy.
- Drones. Prohibited throughout the National Park System.
- Oversized strollers. The main boardwalk is stroller-friendly; side trails are not. A soft baby carrier works everywhere.
Does It Snow?
No. Snow is extremely rare at Muir Woods’ elevation (roughly 150 to 700 feet). Hard frosts happen occasionally on cold winter mornings but melt off quickly.
Frequently Asked Questions
Is Muir Woods open when it rains?
Yes. The monument stays open during the rain season. Trails may close only during dangerous storms or after fallen trees. Check the NPS alerts page before driving out.
How much cooler is Muir Woods than San Francisco?
Typically 5 to 15°F cooler inside the redwood grove, depending on time of day and season. Summer afternoons show the biggest gap.
When does the fog usually burn off?
Summer fog generally thins between late morning and early afternoon. On some heavy marine-layer days it stays socked in all day.
What’s the best month weather-wise?
September. Reliably clear, mild, and dry, with lighter crowds than peak summer.
What should I wear to Muir Woods in summer?
Layer. Morning fog and deep shade keep the forest in the 60s even when San Francisco is in the 80s. A long-sleeve shirt or fleece plus a light shell covers most summer days. Wear closed-toe shoes for the trail.
Do I need a rain jacket?
From October through April, yes. The rest of the year, a light shell is optional but useful for fog drip under the canopy.