Metro areas

Gardening in Fairbanks-College, AK

This metro spans USDA zones 2a to 3b, so there is no single zone for Fairbanks-College, AK and anyone who gives you one is rounding. 56% of its ZIP codes are zone 3b; the rest are not.

USDA zones 2a–3b 3 zones across 9 ZIP codes
ZIP codes 9 9 have a NOAA station within range
Weather stations 8 NOAA 1991–2020 normals, across 7,335 sq mi

Which zone you are in depends where you are

Fairbanks-College, AK covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 56% in zone 3b and wrong for the other 44%. Here is the actual split.

Zone ZIP codes Share  
3b 5 56%
2a 3 33%
2b 1 11%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze May 16 – May 30
First fall freeze August 26 – September 6

Those are the earliest and latest medians among the 8 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 8 stations serving Fairbanks-College, AK it runs 87–112 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 68–72 °F , below the 90 °F point where cool-season crops reliably bolt.

When to start seeds in Fairbanks-College, AK

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 8 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.

Crop Job When Offset
Green Onions Start indoors March 21 – April 4 8 weeks before
Peppers Start indoors March 21 – April 4 8 weeks before
Broccoli Start indoors April 4 – April 18 6 weeks before
Cabbage Start indoors April 4 – April 18 6 weeks before
Collards Start indoors April 4 – April 18 6 weeks before
Kale Start indoors April 4 – April 18 6 weeks before
Leaf Lettuce Start indoors April 4 – April 18 6 weeks before
Peas Direct sow April 4 – April 18 6 weeks before
Spinach Direct sow April 4 – April 18 6 weeks before
Sweet Potato Start indoors April 4 – April 18 6 weeks before
Tomatoes Start indoors April 4 – April 18 6 weeks before
Bok Choy Start indoors April 11 – April 25 5 weeks before
Kohlrabi Start indoors April 11 – April 25 5 weeks before
Swiss Chard Start indoors April 11 – April 25 5 weeks before
Arugula Direct sow April 18 – May 2 4 weeks before
Baby Salad Greens Direct sow April 18 – May 2 4 weeks before
Beets Direct sow April 18 – May 2 4 weeks before
Green Onions Direct sow April 18 – May 2 4 weeks before
Mustard Greens Direct sow April 18 – May 2 4 weeks before
Okra Start indoors April 18 – May 2 4 weeks before
Radishes Direct sow April 18 – May 2 4 weeks before
Turnips Direct sow April 18 – May 2 4 weeks before
Cabbage Set out April 25 – May 9 3 weeks before
Carrots Direct sow April 25 – May 9 3 weeks before
Collards Direct sow April 25 – May 9 3 weeks before
Collards Set out April 25 – May 9 3 weeks before
Cucumbers Start indoors April 25 – May 9 3 weeks before
Green Onions Set out April 25 – May 9 3 weeks before
Kale Direct sow April 25 – May 9 3 weeks before
Kale Set out April 25 – May 9 3 weeks before
Kohlrabi Direct sow April 25 – May 9 3 weeks before
Kohlrabi Set out April 25 – May 9 3 weeks before
Leaf Lettuce Direct sow April 25 – May 9 3 weeks before
Pumpkins Start indoors April 25 – May 9 3 weeks before
Summer Squash Start indoors April 25 – May 9 3 weeks before
Winter Squash Start indoors April 25 – May 9 3 weeks before
Zucchini Start indoors April 25 – May 9 3 weeks before
Bok Choy Direct sow May 2 – May 16 2 weeks before
Bok Choy Set out May 2 – May 16 2 weeks before
Broccoli Set out May 2 – May 16 2 weeks before
Cilantro Direct sow May 2 – May 16 2 weeks before
Leaf Lettuce Set out May 2 – May 16 2 weeks before
Swiss Chard Direct sow May 2 – May 16 2 weeks before
Swiss Chard Set out May 2 – May 16 2 weeks before
Dill Direct sow May 9 – May 23 1 week before
Bush Beans Direct sow May 23 – June 6 1 week after
Cucumbers Set out May 23 – June 6 1 week after
Pumpkins Direct sow May 23 – June 6 1 week after
Pumpkins Set out May 23 – June 6 1 week after
Summer Squash Direct sow May 23 – June 6 1 week after
Summer Squash Set out May 23 – June 6 1 week after
Sweet Corn Direct sow May 23 – June 6 1 week after
Tomatoes Set out May 23 – June 6 1 week after
Winter Squash Direct sow May 23 – June 6 1 week after
Winter Squash Set out May 23 – June 6 1 week after
Zucchini Direct sow May 23 – June 6 1 week after
Zucchini Set out May 23 – June 6 1 week after
Cucumbers Direct sow May 30 – June 13 2 weeks after
Okra Direct sow May 30 – June 13 2 weeks after
Okra Set out May 30 – June 13 2 weeks after
Peppers Set out May 30 – June 13 2 weeks after
Southern Peas Direct sow May 30 – June 13 2 weeks after
Sweet Potato Set out May 30 – June 13 2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Fairbanks-College, AK

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 17 come through the winter in zone 3b and only 3 in zone 2a. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
2a 3 3 of 74 0
2b 1 3 of 74 0
3b 5 17 of 74 0

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 8 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Aurora, AK USC00500490 May 16 September 6 112 days
College Obsy, AK USC00502107 May 18 September 6 111 days
Eielson FLD, AK USC00502707 May 20 September 1 104 days
Ester, AK USC00502870 May 24 September 1 98 days
Mile 42 Steese, AK USC00505880 May 28 August 26 87 days
N Pole, AK USC00506581 May 18 September 5 110 days
Two Rivers, AK USC00509489 May 30 September 2 95 days
Whitestone Farms, AK USC00509793 May 26 September 2 98 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

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