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USDA 2023 hardiness zone · NOAA 1991–2020 frost dates

Frost dates in USDA zone 11a (40 to 45°F)

USDA zone 11a covers places whose coldest winter night averages 40 to 45°F. 1 of 19 stations record a 32°F freeze in at least half of years; for the rest, frost is rare or absent. Enter your ZIP for your local date.

Your ZIP code’s zone and frost dates

Your ZIP gives your zone and the closest NOAA station, which is a better guide than the zone-wide numbers.

5 digits, for example 20001.

From your seed packet, e.g. “start 6 weeks before last frost”.

  • 205ZIP codes in zone 11a40 to 45°F average coldest night
  • 1Stations with frost datesof 19 NOAA stations matched

Stations in zone 11a with a 32°F frost date

Stations in zone 11a with a 32°F frost date: each station’s median (50%) dates
StationLast spring frostFirst fall frost
Perrine 4W, FLJan 18Jan 13

Zone 11a by state

Zone 11a stations by state
StateStationsWith frost dates
California20
Florida151
Hawaii20

Neighboring zones

All hardiness zones

How these numbers are made

Each ZIP code gets one zone from the USDA-ARS / PRISM 2023 ZIP tables, which use the map’s 1991–2020 average of the coldest winter night of each year. A ZIP code can span more than one zone, and USDA’s own lookup works by ZIP or address. Each NOAA station is assigned the most common zone among the closest ZIP codes listed on its station page (a tie goes to the zone of the closest of those ZIPs). Frost dates are NOAA’s 50%-probability (median) 32°F dates for each station, the same values shown on the station pages. Zone figures are the median, 10th and 90th percentile across stations; a first fall frost in January to June is counted in the following year.

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.

Sources

Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.