Last and first frost dates by ZIP code
Your last spring frost is the date the whole vegetable calendar counts from. Find a typical date for your zone, then fine-tune it with local data.
How frost dates are worked out
NOAA's National Centers for Environmental Information publish freeze probabilities for thousands of weather stations as part of the 1991–2020 U.S. Climate Normals. For each station they list the date after which there's a 90%, 50% and 10% chance of a spring freeze, at 36°F, 32°F and 28°F.
The "average" last frost most calendars quote is the 50% date at 32°F. PlotPlan starts from a typical value for your USDA zone. Zones and frost dates are related, since both follow winter cold, but they aren't the same thing: coastal gardens can have mild winters and late spring frosts at the same time.
What to plant around your frost dates
- 4–6 weeks before last frost: peas, spinach, radishes and onion sets can go out; they shrug off light frost.
- 2–3 weeks before: carrots, beets, lettuce, potatoes and brassica transplants.
- 1–2 weeks after: tomatoes, peppers, beans, cucumbers, squash and basil, once soil has warmed.
- 8–12 weeks before first fall frost: sow fall carrots, kale, broccoli and spinach.
The planting calendar does this crop by crop for your dates.
Questions gardeners ask
When is the last frost date for my area?
Enter your ZIP code or zone above for a typical average date. For the most accurate figure, check a nearby weather station in NOAA's 1991–2020 U.S. Climate Normals or ask your county extension office, then type that date into the override box.
What temperature counts as a frost?
Climate records usually use 32°F (0°C) as a light freeze. Tender plants like basil can be damaged at 32°F; a hard freeze of 28°F or below kills most warm-season crops outright.
Can it frost after the last frost date?
Yes. The average last frost date is the 50% point: in about half of years a frost still happens later. Waiting 1–2 weeks lowers the risk considerably, as the explainer on this page shows.
How long is my growing season?
Count the days between your last spring frost and first fall frost. PlotPlan shows this for your zone. Compare it with the "days to maturity" on seed packets to know which varieties will ripen.
Why is my garden colder than the frost date suggests?
Cold air sinks, so low spots and valley bottoms get frost earlier and later than surrounding land. Open, clear, windless nights are the most frost-prone.