Frost Dates by ZIP Code, City and Zone

Enter a ZIP code for the median last and first frost at your nearest NOAA weather station, or browse by zone below.

By HarvestMath Editors October 1, 2026 Share:

Frost Date Calculator

Find your dates by

US ZIP code

Enter a ZIP code or pick your hardiness zone to see your frost dates.

How to read a frost date

Median date: Half of years; have a later last frost than the median, so it is a 50/50 date.
Safer date: 1 year in 10; has a frost after it. Use it for tomatoes and other tender plants.
Your station: Nearest to your ZIP; NOAA 1991–2020 normals, an airport station within 15 miles first.

Across the 14 hardiness zones with a median frost date, the typical last spring frost runs from Jan 27 in zone 10a to May 16 in zone 3b. But a zone rates winter cold, not frost timing: two ZIP codes in the same zone can be weeks apart, which is why every date here comes from the weather station nearest you.

Frost Dates by Hardiness Zone

A zone rates winter cold, not frost timing, so each zone page shows the real spread across its ZIP codes. Pick a zone for its planting schedule.

10th to 90th percentile across the zone's ZIP codes median (the date shown)

Open a zone's frost dates and planting schedule

Frost Dates by State and City

State and city pages are on their way. Until then, the calculator gives any ZIP code's dates, and the planting calendars by state use the same NOAA stations.

Planting calendars by state

More Frost and Planting Tools

A vegetable garden at the edge of spring, with frost on the soil in the morning — An illustration, not a photo of a real garden.

Free book · 23 pages, PDF

The Spacing & Planting Cheat Sheet

When to start, when to plant, how far apart.

Where the dates come from

NOAA's U.S. Climate Normals for 1991 to 2020: the median date of the last 32°F night in spring and the first in fall, at the weather station nearest each ZIP code (an airport station within 15 miles first). The same data drives the Frost Date Calculator, the Seed Starting Calculator and the HarvestMath apps.