Frost dates for ZIP 99921 (Hollis, AK)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Klawock AP, AK (15 miles away).
- Average last spring frostApr 2950% chance of a 32°F freeze after this date
- Average first fall frostOct 1650% chance of a 32°F freeze by this date
- Growing season (frost-free)169 daysmedian, 32°F threshold
- USDA hardiness zone7b5 to 10°F avg. coldest night
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This week in your yard
As of Oct 17, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 99921 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring mid-April to early May.
Fertilizer window
Lawn region: North (cool-season). Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Apr 13 |
| 50% (the "average" last frost) | Apr 29 |
| 10% (cautious: only 1 year in 10 freezes later) | May 14 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Oct 1 |
| 50% (the "average" first frost) | Oct 16 |
| 90% (late: most years have frozen by now) | Nov 5 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 19 | Oct 1 |
| 32°F (freeze) | Apr 29 | Oct 16 |
| 28°F (hard freeze) | Apr 9 | Nov 5 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 99921
Dates count from your average last spring frost (Apr 29) and first fall frost (Oct 16). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 4–18 | May 6–20 (transplant) | – |
| Pepper (sweet and hot) | Feb 18–Mar 4 | May 13–27 (transplant) | – |
| Eggplant | Feb 18–Mar 4 | May 13–27 (transplant) | – |
| Tomatillo | Mar 4–18 | May 6–20 (transplant) | – |
| Lettuce | Mar 4–18 | Apr 8–29 (transplant) Apr 1–May 13 (sow outdoors) | Aug 21–Sep 11 (transplant) Aug 7–Sep 4 (sowing) |
| Spinach | – | Mar 18–Apr 8 (sow outdoors) | Aug 21–Sep 11 (sowing) |
| Kale | Mar 4–18 | Apr 1–15 (transplant) Apr 1–15 (sow outdoors) | Jul 24–Aug 21 (transplant) Jul 10–Aug 7 (sowing) |
| Collards | Mar 4–18 | Apr 1–29 (transplant) Apr 1–29 (sow outdoors) | Jul 24–Aug 21 (transplant) Jul 10–Aug 7 (sowing) |
| Broccoli | Feb 18–Mar 4 | Apr 1–15 (transplant) | Jul 10–Aug 7 (transplant) |
| Cabbage | Feb 18–Mar 4 | Apr 1–15 (transplant) | Jul 10–Aug 7 (transplant) |
| Cauliflower | Feb 18–Mar 4 | Apr 15–29 (transplant) | Jul 10–Aug 7 (transplant) |
| Brussels sprouts | Feb 4–18 | Apr 1–15 (transplant) | Jun 26–Jul 17 (transplant) |
| Kohlrabi | Mar 4–18 | Apr 1–15 (transplant) Apr 1–15 (sow outdoors) | Aug 7–21 (sowing) |
| Bok choy / Asian greens | – | Apr 1–15 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Arugula | – | Apr 1–29 (sow outdoors) | Aug 21–Sep 18 (sowing) |
| Mustard greens | – | Apr 1–22 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Swiss chard | Mar 18–Apr 1 | Apr 15–May 6 (transplant) Apr 15–May 13 (sow outdoors) | Aug 7–21 (sowing) |
| Beet | – | Apr 1–29 (sow outdoors) | Aug 7–21 (sowing) |
| Carrot | – | Apr 8–May 6 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Radish | – | Mar 25–May 6 (sow outdoors) | Sep 4–18 (sowing) |
| Turnip | – | Apr 1–22 (sow outdoors) | Aug 7–21 (sowing) |
| Parsnip | – | Apr 8–29 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 4–Apr 1 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Onion (bulbing) | Feb 4–18 | Mar 18–Apr 1 (transplant) | – |
| Green onion / scallion | – | Mar 18–Apr 15 (sow outdoors) | Aug 7–21 (sowing) |
| Leek | Feb 4–18 | Apr 1–15 (transplant) | – |
| Garlic | – | – | Sep 4–Oct 2 (sowing) |
| Shallot | – | Mar 18–Apr 1 (transplant) | Sep 4–Oct 2 (sowing) |
| Potato | – | Apr 1–15 (transplant) | Jun 26–Jul 10 (transplant) |
| Sweet potato | – | May 20–Jun 3 (transplant) | – |
| Sweet corn | – | May 6–20 (sow outdoors) | – |
| Bean, bush (snap) | – | May 6–20 (sow outdoors) | – |
| Bean, pole | – | May 6–20 (sow outdoors) | – |
| Lima bean | – | May 13–27 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 20–Jun 10 (sow outdoors) | – |
| Cucumber | Apr 1–8 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Summer squash / zucchini | Apr 1–8 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Winter squash | Apr 1–8 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Pumpkin | – | May 6–20 (sow outdoors) | – |
| Watermelon | Apr 1–8 | May 13–27 (transplant) May 13–27 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 1–8 | May 13–27 (transplant) May 13–27 (sow outdoors) | – |
| Okra | Mar 18–Apr 1 | May 13–27 (transplant) May 13–27 (sow outdoors) | – |
| Celery | Feb 4–18 | May 6–13 (transplant) | – |
| Basil | Mar 18–Apr 1 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Cilantro | – | Apr 15–May 13 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Parsley | Feb 18–Mar 4 | Apr 15–29 (transplant) Apr 8–29 (sow outdoors) | – |
| Dill | – | Apr 29–May 13 (sow outdoors) | Aug 21–Sep 4 (sowing) |
| Sunflower | – | Apr 29–May 13 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 1–15 (transplant) | – |
| Rhubarb (crowns) | – | Apr 1–15 (transplant) | – |
| Strawberry (plants) | – | Apr 1–15 (transplant) | Aug 7–Sep 4 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Klawock AP, AK (NOAA GHCN-Daily ID USW00025367), elevation 12 ft, 15.2 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Thorne Bay, AK | 14 mi | May 1 | Oct 13 |
| Craig, AK | 17 mi | Apr 14 | Nov 1 |
| Ketchikan 10N, AK | 35 mi | Apr 20 | Oct 26 |
The average last-frost dates of these stations span 18 days, a rough guide to local variation. See data sources & methods.
Frost questions for 99921
When is the last frost in 99921?
The average (50% chance) last spring freeze of 32°F for ZIP 99921 is April 29. For a more cautious planting date, use May 14, when only 1 year in 10 still sees a later freeze.
When is the first frost in 99921?
The average first fall freeze is October 16. In 1 year in 10 it comes by October 1.
What hardiness zone is 99921?
ZIP 99921 is in USDA zone 7b (5 to 10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 99921 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
99925 Klawock 99919 Thorne Bay 99922 Hydaburg 99918 Coffman Cove 99903 Wrangell 99901 Ketchikan 99926 Metlakatla 99929 Wrangell
Other ZIP codes in Prince of Wales-Hyder Census Area
99830 99836 99918 99919 99922 99923 99925 99926 99927 All Prince of Wales-Hyder Census Area frost dates · Alaska frost dates
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