First & Last Frost Dates by ZIP Code
Enter your ZIP code for your spring and fall frost dates, frost probability bands, growing-season length, and what to plant right now — drawn from 30 years of NOAA weather records. Free, no signup.
What frost dates actually mean
The 32°F line
A "frost date" is the typical date when air temperature falls to 32°F (0°C) — the point where water in plant tissue freezes and tender plants take damage. The last spring frost is the date after which freezing weather usually stops; the first fall frost is when it usually returns. Everything between is your growing season.
Median, not a promise
The headline dates on this page are medians across 1991–2020: in half of those thirty years, the last spring frost came later than the date shown. That's why we show probability bands — the 10% spring date is the cautious choice (only a 1-in-10 chance of frost after it), while the 50% date is the coin flip. Plant tender crops like tomatoes near the cautious end; hardy crops like peas near the early end.
Your garden is not a weather station
Stations sit in open fields, often at airports. Your garden may differ: cold air pools in low spots, so valley gardens frost earlier; walls, fences, and pavement radiate stored heat and buy you a few degrees. Elevation matters enormously — a garden 500 feet above the nearest station can run a week behind it. Treat these dates as a starting point and observe your own yard for a season.
Normals, not forecasts
These are 30-year climate normals — what is typical — not a prediction for this year. A late cold snap can always beat the median. When a freeze is forecast within a week of your planting date, cover tender transplants with row cover or an old sheet; it buys 2–4°F, which is often exactly enough.
Common questions
What is a frost date?
A frost date is the typical calendar date when air temperature drops to 32°F (0°C) — cold enough to damage tender plants. The last spring frost date is when freezing temperatures usually end; the first fall frost date is when they usually return. The days between them are your growing season.
How accurate are these dates?
They are 30-year medians from NOAA weather records (1991–2020) at the nearest station to your ZIP code. They describe what's typical, not what will happen this year. Microclimates — low spots, slopes, nearby buildings, elevation — can shift your real dates by a week or more in either direction.
What does the 10% probability date mean?
In spring, the 10% date means there's only a 10% chance of frost after that date — the cautious planting date. The 50% date is the median: half of years see frost after it. In fall, the 10% date means only a 10% chance of frost before that date.
Why does my ZIP show a station miles away?
Frost dates come from NOAA weather stations, which don't exist in every ZIP code. We match your ZIP to the nearest station with reliable 30-year frost records and tell you exactly how far away it is, so you can judge how well it represents your garden.
Where does the data come from?
Every date on this page is computed from the NOAA National Centers for Environmental Information 1991–2020 U.S. Climate Normals freeze dataset (public domain), using each station's 32°F freeze-probability statistics. Nothing is estimated, interpolated, or guessed.
Is it really free? Any account needed?
Yes — free, no account, no signup. There is no tracking and no cookies. Your ZIP code is looked up locally in your browser and never sent to any server.