Skip to content
ZIP Frost Dates
Menu
USDA 2023 hardiness zone · NOAA 1991–2020 frost dates

Frost dates in USDA zone 8b (15 to 20°F)

USDA zone 8b covers places whose coldest winter night averages 15 to 20°F. Across the 560 NOAA weather stations in zone 8b, the median last spring frost is Mar 19, but it ranges from Mar 8 to Apr 16 for most stations. Enter your ZIP for your local date.

  • Mar 19Median last spring frostmost stations Mar 8–Apr 16
  • Nov 12Median first fall frost50% chance of 32°F by this date
  • 239 daysMedian growing seasonbetween 32°F freezes
  • 3,379ZIP codes in zone 8b15 to 20°F average coldest night
  • 560Stations with frost datesof 560 NOAA stations matched

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”.

Earliest and latest last-frost stations in zone 8b

Earliest median last spring frost, zone 8b
StationLast spring frostFirst fall frost
Nature Park-Beaverton, ORFeb 11Dec 5
Clifton, AZFeb 26Nov 23
Vicksburg City, MSFeb 26Nov 22
Augusta Daniel Field Airport, GAFeb 27Dec 4
Langtry, TXFeb 27Nov 27
Andalusia Opp Airport, ALFeb 28Nov 28
Atmore, ALFeb 28Nov 27
Bay Minette, ALFeb 28Nov 25
Hesperia 2E, CAFeb 28Dec 1
La Tuna 1 S, TXFeb 28Nov 20
Latest median last spring frost, zone 8b
StationLast spring frostFirst fall frost
Mount Charleston Fire Station, NVMay 31Oct 2
Laurel Mountain, ORMay 20Oct 23
Sexton Summit, ORMay 16Oct 30
Corvallis Water Bureau, ORMay 15Oct 8
Yosemite Village 12 W, CAMay 12Nov 1
Glennville, CAMay 11Oct 17
Vernonia #2, ORMay 8Oct 1
Calaveras Big Trees, CAMay 7Oct 28
Dutch Harbor, AKMay 6Oct 18
Ruch, ORMay 4Oct 13

Zone 8b by state

Zone 8b stations by state
StateStationsMedian last frostMedian first frost
Alabama47Mar 17Nov 13
Alaska1May 6Oct 18
Arizona28Apr 1Nov 10
Arkansas18Mar 14Nov 12
California28Apr 16Nov 8
Florida2Mar 15Nov 16
Georgia45Mar 20Nov 13
Louisiana30Mar 10Nov 15
Mississippi49Mar 14Nov 12
Nevada6Mar 25Nov 5
New Mexico2Mar 17Nov 12
North Carolina36Mar 24Nov 13
Oregon50Apr 12Oct 31
South Carolina47Mar 22Nov 12
Texas120Mar 15Nov 15
Utah2Mar 23Nov 7
Virginia5Mar 23Nov 16
Washington44Apr 8Nov 2

Neighboring zones

  • Zone 8a (10 to 15°F): median last frost Mar 30
  • Zone 9a (20 to 25°F): median last frost Mar 4

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.