San Bernardino, CA Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for San Bernardino, California.
Gardening in San Bernardino
The Inland Empire's heat creates growing conditions that coastal California gardeners can only dream about for heat-loving crops. San Bernardino's desert-edge location means hot summers, mild winters, and enough sunshine to ripen anything.
Zone 9b with inland heat amplification. Summer days above 100°F are common, but winters are frost-free enough for citrus. The alluvial soils from the San Bernardino Mountains are deep and fertile with amendment. Water conservation is essential — this is not coastal California's climate.
The city's diverse Latino and Asian communities grow food traditions from Mexico, Vietnam, and the Philippines in backyard gardens that produce year-round in the Inland Empire's generous climate.
What This Means for San Bernardino Gardeners
The average last spring frost in San Bernardino is around February 10, and the average first fall frost arrives around December 5. That gives you approximately 298 frost-free days to work with.
298 days is a long, productive season that supports two full rounds of warm-season crops plus continuous cool-season production through your mild winter. Most frost-sensitive crops can be transplanted by February 10, giving them months to produce before fall. Your winter garden is the real advantage — growing fresh vegetables in December and January while northern gardeners browse seed catalogs.
These dates are based on NOAA 30-year Climate Normal data for the San Bernardino area. Your actual frost dates could shift 2-3 weeks in either direction in any given year. Learn more about our data sources.
What to Grow in San Bernardino
With 298 frost-free days, San Bernardino can grow nearly anything — including tropical and subtropical plants that most of the country can only dream about. Your prime vegetable season runs from fall through spring; summer is for heat-lovers like okra, sweet potatoes, and peppers. Recommended starting points: cherry tomatoes, jalapeños, okra, sweet potatoes, basil, collard greens, tomatillos, and lemongrass.
See the full California planting guide for all 40 plants: California Planting Calendar. Or enter your zip code for exact planting dates personalized to San Bernardino.
More About Zone 9B
San Bernardino is in USDA Hardiness Zone 9B, which means average annual extreme minimum temperatures between 25°F to 30°F. View the full Zone 9B planting guide.
See the complete planting calendar for California: California Planting Calendar.
Other Cities in California
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the San Bernardino area. They represent historical averages, not predictions. In any given year, the actual last frost could be 2-3 weeks earlier or later. Microclimates within San Bernardino (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
You can plant cool-season crops (lettuce, kale, broccoli) from December 5 through February 10 — your cool season is your primary vegetable season. Warm-season crops like tomatoes and peppers go out in early spring. Tropical plants grow year-round. Enter your zip code for exact dates for every plant.