Frost dates for ZIP 99775 (College, 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, College Obsy, AK (0 miles away).
- Average last spring frostMay 1850% chance of a 32°F freeze after this date
- Average first fall frostSep 650% chance of a 32°F freeze by this date
- Growing season (frost-free)111 daysmedian, 32°F threshold
- USDA hardiness zone2b-45 to -40°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 99775 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 7 |
| 50% (the "average" last frost) | May 18 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 1 |
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) | Aug 24 |
| 50% (the "average" first frost) | Sep 6 |
| 90% (late: most years have frozen by now) | Sep 20 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 31 | Aug 26 |
| 32°F (freeze) | May 18 | Sep 6 |
| 28°F (hard freeze) | May 7 | Sep 20 |
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 99775
Dates count from your average last spring frost (May 18) and first fall frost (Sep 6). 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 23–Apr 6 | May 25–Jun 8 (transplant) | – |
| Pepper (sweet and hot) | Mar 9–23 | Jun 1–15 (transplant) | – |
| Eggplant | Mar 9–23 | Jun 1–15 (transplant) | – |
| Tomatillo | Mar 23–Apr 6 | May 25–Jun 8 (transplant) | – |
| Lettuce | Mar 23–Apr 6 | Apr 27–May 18 (transplant) Apr 20–Jun 1 (sow outdoors) | Jul 12–Aug 2 (transplant) Jun 28–Jul 26 (sowing) |
| Spinach | – | Apr 6–27 (sow outdoors) | Jul 12–Aug 2 (sowing) |
| Kale | Mar 23–Apr 6 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | Jun 14–Jul 12 (transplant) May 31–Jun 28 (sowing) |
| Collards | Mar 23–Apr 6 | Apr 20–May 18 (transplant) Apr 20–May 18 (sow outdoors) | Jun 14–Jul 12 (transplant) May 31–Jun 28 (sowing) |
| Broccoli | Mar 9–23 | Apr 20–May 4 (transplant) | May 31–Jun 28 (transplant) |
| Cabbage | Mar 9–23 | Apr 20–May 4 (transplant) | May 31–Jun 28 (transplant) |
| Cauliflower | Mar 9–23 | May 4–18 (transplant) | May 31–Jun 28 (transplant) |
| Brussels sprouts | Feb 23–Mar 9 | Apr 20–May 4 (transplant) | May 17–Jun 7 (transplant) |
| Kohlrabi | Mar 23–Apr 6 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | Jun 28–Jul 12 (sowing) |
| Bok choy / Asian greens | – | Apr 20–May 4 (sow outdoors) | Jul 12–26 (sowing) |
| Arugula | – | Apr 20–May 18 (sow outdoors) | Jul 12–Aug 9 (sowing) |
| Mustard greens | – | Apr 20–May 11 (sow outdoors) | Jul 12–26 (sowing) |
| Swiss chard | Apr 6–20 | May 4–25 (transplant) May 4–Jun 1 (sow outdoors) | Jun 28–Jul 12 (sowing) |
| Beet | – | Apr 20–May 18 (sow outdoors) | Jun 28–Jul 12 (sowing) |
| Carrot | – | Apr 27–May 25 (sow outdoors) | Jun 14–28 (sowing) |
| Radish | – | Apr 13–May 25 (sow outdoors) | Jul 26–Aug 9 (sowing) |
| Turnip | – | Apr 20–May 11 (sow outdoors) | Jun 28–Jul 12 (sowing) |
| Parsnip | – | Apr 27–May 18 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 23–Apr 20 (sow outdoors) | Jun 14–28 (sowing) |
| Onion (bulbing) | Feb 23–Mar 9 | Apr 6–20 (transplant) | – |
| Green onion / scallion | – | Apr 6–May 4 (sow outdoors) | Jun 28–Jul 12 (sowing) |
| Leek | Feb 23–Mar 9 | Apr 20–May 4 (transplant) | – |
| Garlic | – | – | Jul 26–Aug 23 (sowing) |
| Shallot | – | Apr 6–20 (transplant) | Jul 26–Aug 23 (sowing) |
| Potato | – | Apr 20–May 4 (transplant) | May 17–31 (transplant) |
| Sweet potato | – | Jun 8–22 (transplant) | – |
| Sweet corn | – | May 25–Jun 8 (sow outdoors) | – |
| Bean, bush (snap) | – | May 25–Jun 8 (sow outdoors) | – |
| Bean, pole | – | May 25–Jun 8 (sow outdoors) | – |
| Lima bean | – | Jun 1–15 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 8–29 (sow outdoors) | – |
| Cucumber | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Summer squash / zucchini | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Winter squash | Apr 20–27 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Pumpkin | – | May 25–Jun 8 (sow outdoors) | – |
| Watermelon | Apr 20–27 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 20–27 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Okra | Apr 6–20 | Jun 1–15 (transplant) Jun 1–15 (sow outdoors) | – |
| Celery | Feb 23–Mar 9 | May 25–Jun 1 (transplant) | – |
| Basil | Apr 6–20 | May 25–Jun 8 (transplant) May 25–Jun 8 (sow outdoors) | – |
| Cilantro | – | May 4–Jun 1 (sow outdoors) | Jul 12–26 (sowing) |
| Parsley | Mar 9–23 | May 4–18 (transplant) Apr 27–May 18 (sow outdoors) | – |
| Dill | – | May 18–Jun 1 (sow outdoors) | Jul 12–26 (sowing) |
| Sunflower | – | May 18–Jun 1 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 20–May 4 (transplant) | – |
| Rhubarb (crowns) | – | Apr 20–May 4 (transplant) | – |
| Strawberry (plants) | – | Apr 20–May 4 (transplant) | Jun 28–Jul 26 (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: College Obsy, AK (NOAA GHCN-Daily ID USC00502107), elevation 597 ft, 0.4 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| University EXP STN, AK | 1 mi | May 16 | Sep 8 |
| Fairbanks Midtown, AK | 2 mi | May 13 | Sep 10 |
| Fairbanks AP #2, AK | 3 mi | May 16 | Sep 8 |
The average last-frost dates of these stations span 5 days, a rough guide to local variation. See data sources & methods.
Frost questions for 99775
When is the last frost in 99775?
The average (50% chance) last spring freeze of 32°F for ZIP 99775 is May 18. For a more cautious planting date, use June 1, when only 1 year in 10 still sees a later freeze.
When is the first frost in 99775?
The average first fall freeze is September 6. In 1 year in 10 it comes by August 24.
What hardiness zone is 99775?
ZIP 99775 is in USDA zone 2b (-45 to -40°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 99775 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
99725 Ester 99703 Fairbanks 99709 Goldstream 99705 Badger 99702 Eielson AFB 99790 Livengood 99758 Minto 99760 Nenana
Other ZIP codes in Fairbanks North Star Borough
99702 99703 99705 99707 99709 99712 99714 99725 All Fairbanks North Star Borough frost dates · Alaska frost dates
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