USDA hardiness zone
Zone 3a
Rolled up from the 25 ZIP codes in our data that are classified zone 3a, covering 5 nurseries and garden centers across 1 cities we track in this zone.
Average minimum winter temperature
-40°F
Last spring frost range
May 1–Jun 10
First fall frost range
Sep 3–Oct 1
Average frost-free growing season
119 days
Average monthly temperature
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2° | 7.2° | 16.3° | 32° | 46.7° | 57.4° | 61.6° | 58.7° | 49.5° | 34.7° | 18.9° | 7.7° |
NOAA 1991–2020 Climate Normals, averaged across this zone's member ZIPs.
Crops by frost hardiness
What grows here, and when
This zone's own last-frost dates range across May 1–Jun 10. Hardy and semi-hardy crops can go in before that date; tender and very-tender crops need to wait until after it. See each crop's own guide for exact windows at a specific location in this zone.
Planting windows and crop timing here are computed from USDA/NOAA climate data and the university extension sources cited below, not a site visit or soil test. Treat this as a starting point: local conditions vary, and a local nursery or extension office can advise on your exact site. See our full Disclaimer.
Hardy (49)
- Apple (bare-root fruit tree)
- Apricot (bare-root fruit tree)
- Asparagus
- Bachelor's Button (Cornflower)
- Bare-root rose
- Blackberry
- Blueberry
- Broccoli
- Brussels Sprouts
- Cabbage
- Calendula
- Catnip/Catmint
- Cherry (sweet/tart, bare-root fruit tree)
- Chives
- Collards
- Currant
- Deciduous shade tree (generic, e.g. maple/oak, bare-root or B&B)
- Elderberry
- Evergreen shrub (B&B/potted, e.g. arborvitae, boxwood)
- Flowering deciduous shrub (generic, e.g. lilac/forsythia)
- Garden Peas
- Garlic
- Gooseberry
- Kale
- Kohlrabi
- Larkspur
- Lavender
- Lettuce
- Mint
- Onion (bulb)
- Oregano
- Peach (bare-root fruit tree)
- Pear (bare-root fruit tree)
- Plum (bare-root fruit tree)
- Radish
- Raspberry
- Rhubarb
- Rutabaga
- Sage
- Snapdragon
- Snow Peas
- Spinach
- Strawberry
- Sweet Alyssum
- Sweet Pea
- Table/Bunch Grape
- Tarragon
- Thyme
- Turnip
Semi-hardy (16)
Tender (20)
Zone 3a means an average annual extreme minimum winter temperature of -40°F to -35°F on the 2023 USDA Plant Hardiness Zone Map (USDA/ARS with the PRISM Climate Group at Oregon State University, 1991-2020 records). Every ZIP in this rollup carries its zone matched by centroid against the map, not by its polygon boundary, via phzmapi.org's ZIP-level derivation.
The frost and growing-season figures above are the real numbers for this zone's own ZIPs, and they set a hard ceiling on what's realistic here: at this length of season, a crop's own days-to-maturity number, not just its frost tolerance, decides whether it finishes before the cold returns. Zone 3a says nothing about summer heat, rainfall, or day length, only about how cold the coldest night gets.
We track 5 nurseries in zone 3a, all in Anchorage, the only city we cover in this band.
Cities we track in zone 3a
- Anchorage, AK (5)
Nearby zones
All zones
USDA 2023 Plant Hardiness Zone Map (zone boundaries, via the phzmapi.org ZIP-level derivation) and NOAA 1991–2020 Climate Normals (frost dates, growing season, monthly temperatures).