When to plant in Anchorage, AK
USDA Zone 5aEverything below — frost dates, hardiness zone, and what to plant when in Anchorage, Alaska — is derived from the closest NOAA station with complete climate normals.
Zone 5a means Anchorage sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
EAGLE RVR NATURE CTR · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Anchorage’s own odds, recorded at EAGLE RVR NATURE CTR.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jul 2 | May 31 | May 19 | Aug 21 | Sep 6 | Sep 22 |
| 32°F | Jun 9 | May 16 | May 2 | Sep 4 | Sep 20 | Oct 3 |
| 28°F | May 15 | May 1 | Apr 16 | Sep 18 | Oct 1 | Oct 16 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Anchorage, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 20 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Anchorage planting FAQ
When is the last spring frost in Anchorage, AK?
Plan for the last spring frost in Anchorage around May 16 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Anchorage, AK?
In Anchorage, the first 32°F freeze of fall lands around September 20 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Anchorage in?
Anchorage is in USDA hardiness zone 5a. In zone 5a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Anchorage?
There are roughly 127 frost-free days in Anchorage (a short growing season), running from the average last frost around May 16 to the first fall frost near September 20.
When should I plant tomatoes in Anchorage?
In Anchorage, start tomato seeds indoors around March 21–April 4, then transplant seedlings outdoors around May 23 once the danger of frost has passed.
Never miss a window in Anchorage
An email when it’s time to start seeds, transplant, and sow — timed to Anchorage’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Knik-Fairview · 41 km
- North Lakes · 49 km
- Badger · 415 km
- Fairbanks · 415 km
- College · 417 km
- Juneau city and · 899 km
- Birch Bay · 2145 km
- Lynden · 2157 km
Frost dates recorded at EAGLE RVR NATURE CTR, 7 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Anchorage, AK — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00502642. Retrieved from https://blissgarden.com/alaska/anchorage.