Tucson, AZ Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Tucson, Arizona.
Gardening in Tucson
Tucson embraces the desert in a way Phoenix doesn't always. The city's food garden culture draws on 4,000 years of Sonoran Desert agriculture — the Tohono O'odham and other Indigenous peoples were growing food in this landscape millennia before modern irrigation arrived.
Tucson's slightly higher elevation (2,400 feet) and slightly cooler temperatures compared to Phoenix make it marginally easier on gardens, but this is still genuine desert. Your 278-day growing season sounds generous, but roughly 120 of those days are simply too hot for most crops. The monsoon season (July-September) brings dramatic afternoon thunderstorms that provide free irrigation and a welcome humidity boost.
Tucson was designated a UNESCO City of Gastronomy — the first in the US — partly because of its deep food-growing heritage. The Mission Garden project is recreating 4,000 years of Tucson-area agriculture. Community gardens like the Dunbar Spring neighborhood garden prove that desert food production is both possible and beautiful.
What This Means for Tucson Gardeners
The average last spring frost in Tucson is around February 20, and the average first fall frost arrives around November 25. That gives you approximately 278 frost-free days to work with.
278 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 20, 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 Tucson 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 Tucson
Tucson's 278-day growing season is generous — long enough for two full growing windows (spring and fall) with warm-season crops between them. You can grow the full range of vegetables, herbs, and flowers with proper timing. Focus on heat-tolerant varieties for midsummer and cool-season crops for extended fall harvests. Recommended starting points: tomatoes, peppers, beans, cucumbers, squash, garlic, kale, and sunflowers.
See the full Arizona planting guide for all 40 plants: Arizona Planting Calendar. Or enter your zip code for exact planting dates personalized to Tucson.
More About Zone 9A
Tucson is in USDA Hardiness Zone 9A, which means average annual extreme minimum temperatures between 20°F to 25°F. View the full Zone 9A planting guide.
See the complete planting calendar for Arizona: Arizona Planting Calendar.
Other Cities in Arizona
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Tucson 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 Tucson (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Cool-season crops go in 3-4 weeks before your last frost (February 20). Warm-season crops wait until 2 weeks after. You have time for a fall round too — plant cool-season crops again in late summer for harvest into autumn. Enter your zip code for exact dates.