May in Northern California
May is the first month that feels like summer in most of NorCal, and the first week of June is the last you can pretend it's spring. Wildflowers move up the elevation line, Sierra trails start opening, farmers markets explode, and the coast plays fog-and-sun tag.
What's happening outside
Wildflowers: now at elevation
The foothill bloom is done by mid-May, but the mid-elevation bloom (2,500 to 5,000 ft) is at its best. Try:
- Bear Valley near Leavitt Meadow: mule's ears, lupine, paintbrush.
- Lassen foothills: along Highway 36 east of Red Bluff.
- Ed Z'berg Sugar Pine Point (Tahoe): forest-floor flowers once the snow is off.
Alpine bloom doesn't start until July in most of the Sierra.
Sierra trails start opening
Low-elevation Sierra trails (under 6,000 ft) are hikeable by mid-May in a normal year. Higher passes, Tioga Road in Yosemite, Sonora Pass: usually Memorial Day at earliest, sometimes mid-June. Check the Yosemite and Caltrans pass status pages before committing.
Delta and river fishing
Striped bass fishing on the Delta and Sacramento River is at its best from late April through mid-May. American shad run up the Feather and American rivers in May. Lower flow than April (snowmelt spiked in April, tapers in May) means the water is still cold but wadable.
Fog starts its routine
The classic NorCal summer pattern starts locking in: hot inland pulls cool air off the ocean, which pulls in the fog at the coast. By late May, San Francisco can be 55 F and foggy while Walnut Creek is 88 F. Pack layers for anything involving the coast, even when it's a heat wave inland.
On the farms
- Strawberries: in full swing. Watsonville and Salinas pricing drops by half.
- Cherries: start showing up late May from the Brentwood and Linden orchards.
- Stone fruit: first apricots, early peaches by the last week of May.
- Bok choy, peas, spring onions: peak at Bay Area and Sacramento markets.
Festivals and events (real ones, not the touristy ones)
- Bay to Breakers (SF): third Sunday of May. Not for everyone. Very much a thing.
- Davis Whole Earth Festival: second weekend. Cooperative, mellow, nothing like a food truck festival.
- Sacramento Jazz Jubilee (Memorial Day weekend): old-school, traditional jazz. Go early.
What to skip
Yosemite Valley on Memorial Day weekend unless you already have a permit and a plan. Entry is timed-entry through October. Plan for the park in April or September, not May.