What’s in season in the Bay Area? Something, all year

In most of the United States, asking what’s in season gets you a real answer and, for several months a year, a sad one. Asking what’s in season in the Bay Area gets you a different kind of answer: it depends on the month, but it is never “nothing.” This is not local boosterism; it is climate. The Bay Area sits in one of the world’s five Mediterranean climate zones — a category covering, as the UC Marin Master Gardeners put it, just 2 percent of the Earth’s land while holding 20 percent of its plant species. Mild wet winters and dry warm summers mean the region runs two overlapping growing calendars instead of one, and the local food supply never actually goes dark.

Why does the Bay Area have a twelve-month season?

The Mediterranean pattern splits the year into two productive halves rather than a growing season and a dead one. Summers are warm and rainless — good for everything that loves heat, from tomatoes to melons, wherever irrigation reaches. Winters are wet but mild: hard frost is rare near the coast, and UC ANR’s Alameda County master gardeners note that the classic cool-season vegetables actually prefer this weather, thriving when average temperatures sit between 55 and 75 degrees. So while the upper Midwest waits under snow, Bay Area fields are in active production — just of different crops. The result is not one long summer; it is a relay, with the baton passing in roughly November and April.

The fog is a feature

The second trick is the marine layer. The summer fog that tourists curse is a natural cooling system for the coastal strips from Marin down through the Santa Cruz and Monterey coasts, and it is why the Bay Area keeps eating local salad in August. Lettuces, spinach, arugula, and the cabbage family are cool-season crops; in hot-summer climates they bolt — race to seed and turn bitter — the moment July arrives. The Alameda County master gardeners make the point directly: these vegetables grow more abundantly in cooler weather and do not bolt as readily as they do on hot days. The fog belt manufactures that cooler weather all summer long, which is why coastal California can grow the crops of a northern spring in the middle of its own heat season.

The corollary is that the Bay Area is not one climate but a mosaic of them. The UC Marin Master Gardeners build their whole planting guidance around microclimates for a reason: cross twenty miles from the fog line to an inland valley and you move between growing worlds. For a shopper, that mosaic is why “what’s in season” can differ between two farmers markets on the same Saturday — the coastal table is heavy on greens and berries while the inland one is already drowning in tomatoes. Neither is wrong. They are different farms answering different weather.

Winter is the plot twist

Winter is where the Bay Area diverges hardest from the national script. December through February is citrus season — mandarins, navels, lemons — arriving exactly when the rest of the produce world thins out. Alongside it runs the full cool-season roster that UC ANR’s Bay Area gardening guides catalog: cauliflower, broccoli, brussels sprouts, cabbage, collards, kale, and bok choy; spinach, lettuce, arugula, and chard; carrots, beets, turnips, and peas. Foodwise — the nonprofit formerly known as CUESA that runs San Francisco’s Ferry Plaza Farmers Market — publishes seasonality charts tracking what actually shows up at its Bay Area markets, and those charts keep a winter column for a reason. The market itself runs Saturdays, Tuesdays, and Thursdays every week of the year, which is only possible because the farms supplying it never fully stop.

A season-by-season sketch

• Winter (December–February): citrus at full strength, the brassica family at its sweetest, hardy greens, and root vegetables — the quietest season, and still a full table.
• Spring (March–May): asparagus and artichokes, peas and favas, the first strawberries, and green everything as the winter rains pay out.
• Summer (June–August): the flood — stone fruit, tomatoes, sweet corn, peppers, melons, and berries, with coastal greens running right through the heat thanks to the fog.
• Fall (September–November): apples, pears, grapes, and figs give way to pomegranates, persimmons, and winter squash as the first rains return and the cycle resets.

The Central Valley backbone

The honest footnote to Bay Area abundance is that much of it drives in from over the hills. The coastal counties grow world-class greens, brassicas, and berries, but the sheer variety on a Bay Area market table leans on the Central Valley — the stone fruit, tomatoes, melons, grapes, nuts, and citrus country that makes California the outlier it is. The state’s own agricultural statistics are almost implausible: per CDFA, California farms received $61.2 billion in cash receipts in 2024 across more than 400 commodities. “Local” in the Bay Area quietly means a couple of hundred miles at most — a morning’s drive — which is a looser definition than a Vermonter’s, and a far fresher reality than a supermarket’s.

The practical upshot: in the Bay Area, eating seasonally is not a sacrifice discipline, it is a navigation problem — the food is out there every month; the question is which stand, market, or farm share has it this week. The FarmHop iPhone app maps the farm stands, farmers markets, and CSAs near you — part of 90,000+ US listings, each carrying a verification badge and a last-checked date — which is genuinely useful in a place where the season never closes, only rotates. Twelve months a year, something within an hour of you was picked this morning. That fact is the whole argument.