USDA hardiness zones — 2023 map
Alaska hardiness zones — USDA planting zone map + what to grow
Zones 1a-8b · most of Alaska is zone 4b · Pacific region
AlaskaUSDA zone range & map
On the 2023 USDA Plant Hardiness Zone Map, Alaska spans zones 1a-8b. The map shades the state from the interior near Fairbanks (zone 1a-2b) through to the southeast coast and panhandle around Sitka (zone 8b). The single most common half-zone across the populated state is zone 4b — that is the figure to use if you only remember one number for Alaska. Alaska spans the widest zone range of any state, from sub-arctic interior to mild maritime southeast. Season length and summer light, not just cold, shape what grows.
| USDA zone range | Zones 1a-8b |
|---|---|
| Most common zone | Zone 4b |
| Coldest area | the interior near Fairbanks (zone 1a-2b) |
| Warmest area | the southeast coast and panhandle around Sitka (zone 8b) |
| Average last spring frost | late May |
| Average first fall frost | mid-September |
Source: USDA 2023 Plant Hardiness Zone Map (1991-2020 normals). Frost averages: NOAA/NCEI 1991-2020 climate normals. Local ZIP-level zones and frost dates can differ from these statewide figures.
Alaska hardiness zones by major city
Zones shift across Alaska with elevation and distance from the coast. Here is the 2023 USDA half-zone for the largest cities:
| City | USDA zone |
|---|---|
| Anchorage | Zone 5a |
| Fairbanks | Zone 2a |
| Juneau | Zone 7a |
| Sitka | Zone 8a |
Need your exact zone? Run the ZIP-code zone finder for a precise half-zone and frost dates for your address.
ZIP-code zones in Alaska
Statewide ranges hide a lot. Tap your area for its exact USDA half-zone, last and first frost dates, and what to plant now:
- Anchorage 99501 — Zone 5a
- Anchorage (East) 99504 — Zone 4b
- Anchorage (Midtown) 99508 — Zone 5a
- Anchorage (South) 99515 — Zone 5a
- Homer 99603 — Zone 5b
- Palmer 99645 — Zone 4a
- Wasilla 99654 — Zone 4a
- Fairbanks 99701 — Zone 2a
- Fairbanks (College) 99709 — Zone 2b
- Juneau 99801 — Zone 6b
- Ketchikan 99901 — Zone 7a
What Alaska's zone range means for planting
Your hardiness zone tells you which perennials, shrubs, and trees will survive a typical Alaska winter, and it anchors when tender crops can go outside. Because Alaska spans 1a-8b, two gardeners in the same state can have very different planting calendars.
- Pick perennials hardy to your local zone. Across most of Alaska that means at least zone 4b; gardeners in the interior near Fairbanks (zone 1a-2b) should choose hardier plants.
- Anchor tender crops to your frost dates. With a last spring frost around late May and first fall frost around mid-September, set out tomatoes, peppers, and basil after the last frost and protect them before the first.
- Adjust for your microclimate. Urban heat, a south-facing slope, or a cold valley pocket can shift your effective zone and frost dates by a half-zone or more from the statewide figure.
Find your exact zone in Alaska
The 1a-8b range is statewide. Growli pins your hardiness zone and frost dates to your exact ZIP code and sends a push notification before any forecast frost night for your saved location.
Frequently asked questions
What hardiness zone is Alaska?
Alaska spans USDA hardiness zones 1a-8b on the 2023 USDA Plant Hardiness Zone Map. The most common zone — covering the largest share of the populated state — is zone 4b. The coldest areas are the interior near Fairbanks (zone 1a-2b) and the warmest are the southeast coast and panhandle around Sitka (zone 8b).
When is the last frost in Alaska?
Across most of Alaska the average last spring frost falls around late May and the first fall frost around mid-September. These are statewide averages — colder, higher areas run later in spring and earlier in fall, so check a ZIP-level estimate for your exact spot.
What grows well in Alaska?
Alaska spans the widest zone range of any state, from sub-arctic interior to mild maritime southeast. Season length and summer light, not just cold, shape what grows. Match plants to your local half-zone within the 1a-8b range: choose varieties hardy to at least zone 4b for reliable overwintering, and time tender crops around your local frost dates. The zone 4 planting guide lists vegetables, fruit, and ornamentals suited to most of the state.
Why does Alaska have more than one hardiness zone?
Hardiness zones track the average annual coldest temperature, which changes with latitude, elevation, distance from water, and urban heat. That is why Alaska ranges from the interior near Fairbanks (zone 1a-2b) to the southeast coast and panhandle around Sitka (zone 8b) — a span of 1a-8b — even though it is a single state.
Did Alaska's hardiness zone change in 2023?
The USDA updated the Plant Hardiness Zone Map in November 2023 using 1991-2020 climate data. About half the country, including parts of Alaska, shifted to the next warmer half-zone versus the 2012 map. The 1a-8b range here reflects the current 2023 map. Always confirm your address against the official USDA map for plant-survival decisions.