Mill Valley Mushroom Calendar

Mill Valley sits in the Central California Foothills and Coastal Mountains and has a damp, maritime-influenced climate — about 44.4 inches of rain a year, most of it falling in the cool months from fall into spring. Mushroom season around Mill Valley waxes and wanes with the rains but never truly closes — hard frost is rare enough here that there's no sharp start or end to the year. Summer dries out — June through September typically see under an inch of rain — and fruiting goes quiet until the rains return in October, kicking off the year's main flush.

Best months January, November, and December
Ground warms ~January
Hard frost rare
Annual rain 44.4"
Driest June through September
Species tracked 14

What Fruits When Near Mill Valley

JFMAMJJASONDMorelKing BoleteMatsutakeChanterelleHedgehogOysterLobsterregLion's Mane / Bear's HeadBlewitThe PrinceShaggy ManeBlack TrumpetCandy CapChicken of the WoodsYellowfoot

Shading shows when each species typically fruits within about 10 miles, not abundance. Based on iNaturalist observation trends. reg = pooled from the surrounding area where local sightings were sparse.

The Shape of the Season

All species combined — local observations within about 10 miles, by month.

Weather Through the Year

Average daily high–low (°F)

Average monthly precipitation (inches)

The Forest Around Mill Valley

Dominant tree species within about 10 km — the hosts that shape which mushrooms grow here.

  • Douglas-fir62.2%
  • Redwood33.6%
  • Pacific Madrone4.1%

Species to Know Near Mill Valley

Blewit Blewit Peaks in January Photo: Jeremy Collison (CC BY-NC)

Common Questions

When is mushroom season in Mill Valley?

Near Mill Valley, mushroom season runs through the wet winter: the first soaking fall storms open it and it peaks in the cool, rainy months. The strongest months in the local observation record are January, November, and December.

When do morels fruit near Mill Valley?

Morel reports near Mill Valley peak in March. Timing tracks soil temperature, so south-facing slopes and lower elevations start earlier and higher ground runs later.

What mushrooms grow near Mill Valley?

14 species show up in the observation record within about 10 miles of Mill Valley, including Morel, King Bolete, Matsutake, Chanterelle, Hedgehog, Oyster, Lion's Mane / Bear's Head, Blewit. The calendar above shows when each one typically fruits.

Want live conditions instead of climatology? The Forayz map layers soil moisture, soil temperature, snow cover, and recent burns over the same area.

Nearby Calendars in Northern California

Climate normals: NOAA NCEI U.S. Climate Normals (1991–2020). Season-onset timing is an air-temperature proxy, not a soil reading.