NOAA 1991–2020 normals · 40,502 ZIP codes

Know your last frost date before you plant

Enter a ZIP code to get your last spring and first fall frost dates at the risk level you choose, your USDA hardiness zone, and the date to start seeds or set out transplants.

Last spring and first fall frost dates at 10%, 50% and 90% risk
Your 2023 USDA hardiness zone and growing-season length
A planting date counted from your seed packet’s weeks

Find my frost dates Browse states

7,283 NOAA stations · 40,502 ZIP codes with zones · 30 years of freeze records

Frost dates: NOAA NCEI normals, file dated June 27, 2023Zones: USDA-ARS / OSU PRISM 2023 ZIP tablesZIP locations: Census 2024Independent; not a government site

6,948 stations

have spring and fall 32°F freeze dates computed by NOAA from 1991–2020 records.

33,475 ZIPs

are matched to their closest station. 211 of them are more than 40 km away, and we flag that in the result.

3 risk levels

For example, at Washington Reagan National Airport the last 32°F frost has a 90% chance of being over by Apr 6, 50% by Mar 24 and 10% by Mar 7.

How to read frost dates

Pick a risk level

“Median” means a frost after that date happens in half of years. Gardeners with tender plants such as tomatoes usually wait for the 10% date.

Count from the date

Seed packets say things like “start indoors 6 weeks before last frost”. Enter that number and the calculator gives the calendar date.

Check the zone

Your hardiness zone tells you which perennials survive winter. It comes from average extreme winter lows, not frost dates.

Read the full method and sources

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Browse by state

Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.