Frost dates for Port Alsworth, AK
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
June 2
typical year
Safe to plant
June 13
frost is over in 9 of 10 years
First fall frost
September 12
typical year
Growing season
101 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | May 5 – 19 | – |
| Spinach | – | Apr 21 – May 12 | Jul 18 – Aug 1 |
| Lettuce | – | May 5 – 26 | Jul 18 – Aug 1 |
| Radishes | – | May 5 – Jun 16 | Aug 1 – 15 |
| Onions | – | May 5 – 19 | – |
| Potatoes | – | May 12 – 26 | – |
| Carrots | – | May 12 – Jun 2 | Jun 20 – Jul 4 |
| Beets | – | May 5 – 19 | Jul 4 – 18 |
| Kale | Mar 24 – Apr 7 | May 5 – 19 | Jul 4 – 18 |
| Broccoli | Mar 24 – Apr 7 | May 19 – Jun 2 | Jul 4 – 18 |
| Cabbage | Mar 10 – 24 | May 5 – 19 | Jul 4 – 18 |
| Garlic | – | – | Aug 1 – 22 |
| Warm-season crops | |||
| Tomatoes | Apr 18 – May 2 | Jun 13 – 27 | – |
| Peppers | Apr 11 – 25 | Jun 20 – Jul 4 | – |
| Cucumbers | – | Jun 13 – Jul 4 | – |
| Zucchini | – | Jun 13 – Jul 11 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 13 – Jul 4 | – |
| Sweet corn | – | Jun 13 – Jul 11 | – |
| Basil | May 9 – 23 | Jun 20 – 27 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | June 13 | June 2 | May 22 |
| Fall frost before | August 29 | September 12 | September 25 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around May 19 (May 30 in a late year), and the first one in fall around September 25.
Where these dates come from
NOAA weather station PORT ALSWORTH 1 SW, AK US (USW00026562), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 23 miles:
99647, 99653
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.