Frost dates for ZIP 99639 (Ninilchik, 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, Homer 8 NW, AK (17 miles away).
- Average last spring frostMay 1650% chance of a 32°F freeze after this date
- Average first fall frostSep 3050% chance of a 32°F freeze by this date
- Growing season (frost-free)136 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 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
38°F Below 50°F
24-hour average · latest 38°F, as of Oct 17, 10:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Moose Inc (21 mi).
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 99639 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) | May 1 |
| 50% (the "average" last frost) | May 16 |
| 10% (cautious: only 1 year in 10 freezes later) | May 30 |
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) | Sep 16 |
| 50% (the "average" first frost) | Sep 30 |
| 90% (late: most years have frozen by now) | Oct 14 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 3 | Sep 17 |
| 32°F (freeze) | May 16 | Sep 30 |
| 28°F (hard freeze) | Apr 29 | Oct 11 |
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 99639
Dates count from your average last spring frost (May 16) and first fall frost (Sep 30). 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 21–Apr 4 | May 23–Jun 6 (transplant) | – |
| Pepper (sweet and hot) | Mar 7–21 | May 30–Jun 13 (transplant) | – |
| Eggplant | Mar 7–21 | May 30–Jun 13 (transplant) | – |
| Tomatillo | Mar 21–Apr 4 | May 23–Jun 6 (transplant) | – |
| Lettuce | Mar 21–Apr 4 | Apr 25–May 16 (transplant) Apr 18–May 30 (sow outdoors) | Aug 5–26 (transplant) Jul 22–Aug 19 (sowing) |
| Spinach | – | Apr 4–25 (sow outdoors) | Aug 5–26 (sowing) |
| Kale | Mar 21–Apr 4 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | Jul 8–Aug 5 (transplant) Jun 24–Jul 22 (sowing) |
| Collards | Mar 21–Apr 4 | Apr 18–May 16 (transplant) Apr 18–May 16 (sow outdoors) | Jul 8–Aug 5 (transplant) Jun 24–Jul 22 (sowing) |
| Broccoli | Mar 7–21 | Apr 18–May 2 (transplant) | Jun 24–Jul 22 (transplant) |
| Cabbage | Mar 7–21 | Apr 18–May 2 (transplant) | Jun 24–Jul 22 (transplant) |
| Cauliflower | Mar 7–21 | May 2–16 (transplant) | Jun 24–Jul 22 (transplant) |
| Brussels sprouts | Feb 21–Mar 7 | Apr 18–May 2 (transplant) | Jun 10–Jul 1 (transplant) |
| Kohlrabi | Mar 21–Apr 4 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Bok choy / Asian greens | – | Apr 18–May 2 (sow outdoors) | Aug 5–19 (sowing) |
| Arugula | – | Apr 18–May 16 (sow outdoors) | Aug 5–Sep 2 (sowing) |
| Mustard greens | – | Apr 18–May 9 (sow outdoors) | Aug 5–19 (sowing) |
| Swiss chard | Apr 4–18 | May 2–23 (transplant) May 2–30 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Beet | – | Apr 18–May 16 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Carrot | – | Apr 25–May 23 (sow outdoors) | Jul 8–22 (sowing) |
| Radish | – | Apr 11–May 23 (sow outdoors) | Aug 19–Sep 2 (sowing) |
| Turnip | – | Apr 18–May 9 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Parsnip | – | Apr 25–May 16 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 21–Apr 18 (sow outdoors) | Jul 8–22 (sowing) |
| Onion (bulbing) | Feb 21–Mar 7 | Apr 4–18 (transplant) | – |
| Green onion / scallion | – | Apr 4–May 2 (sow outdoors) | Jul 22–Aug 5 (sowing) |
| Leek | Feb 21–Mar 7 | Apr 18–May 2 (transplant) | – |
| Garlic | – | – | Aug 19–Sep 16 (sowing) |
| Shallot | – | Apr 4–18 (transplant) | Aug 19–Sep 16 (sowing) |
| Potato | – | Apr 18–May 2 (transplant) | Jun 10–24 (transplant) |
| Sweet potato | – | Jun 6–20 (transplant) | – |
| Sweet corn | – | May 23–Jun 6 (sow outdoors) | – |
| Bean, bush (snap) | – | May 23–Jun 6 (sow outdoors) | – |
| Bean, pole | – | May 23–Jun 6 (sow outdoors) | – |
| Lima bean | – | May 30–Jun 13 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 6–27 (sow outdoors) | – |
| Cucumber | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Summer squash / zucchini | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Winter squash | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Pumpkin | – | May 23–Jun 6 (sow outdoors) | – |
| Watermelon | Apr 18–25 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 18–25 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Okra | Apr 4–18 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Celery | Feb 21–Mar 7 | May 23–30 (transplant) | – |
| Basil | Apr 4–18 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Cilantro | – | May 2–30 (sow outdoors) | Aug 5–19 (sowing) |
| Parsley | Mar 7–21 | May 2–16 (transplant) Apr 25–May 16 (sow outdoors) | – |
| Dill | – | May 16–30 (sow outdoors) | Aug 5–19 (sowing) |
| Sunflower | – | May 16–30 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 18–May 2 (transplant) | – |
| Rhubarb (crowns) | – | Apr 18–May 2 (transplant) | – |
| Strawberry (plants) | – | Apr 18–May 2 (transplant) | Jul 22–Aug 19 (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: Homer 8 NW, AK (NOAA GHCN-Daily ID USC00503672), elevation 1,080 ft, 17.2 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Homer 9 E, AK | 20 mi | May 27 | Sep 22 |
| Homer AP, AK | 24 mi | May 10 | Sep 29 |
| Soldotna 5SSW, AK | 33 mi | Jun 11 | Sep 1 |
The average last-frost dates of these stations span 32 days, a rough guide to local variation. See data sources & methods.
Frost questions for 99639
When is the last frost in 99639?
The average (50% chance) last spring freeze of 32°F for ZIP 99639 is May 16. For a more cautious planting date, use May 30, when only 1 year in 10 still sees a later freeze.
When is the first frost in 99639?
The average first fall freeze is September 30. In 1 year in 10 it comes by September 16.
What hardiness zone is 99639?
ZIP 99639 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 99639 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
99556 Anchor Point 99610 Cohoe 99669 Kalifornsky 99603 Fox River 99568 Clam Gulch 99663 Seldovia Village 99672 Sterling 99611 Nikiski
Other ZIP codes in Kenai Peninsula Borough
99556 99568 99572 99603 99605 99610 99611 99631 99635 99663 99664 99669 99672 99682 All Kenai Peninsula Borough frost dates · Alaska frost dates
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