Frost dates for Belfast, ME
NOAA weather station USC00170480 at 20 ft elevation. Based on 30 years within 1991-2020. Last verified 2026-10-17.
Last spring freeze (32°F)
May 7
median: freeze still happened after this date in half of years
May 13 30% risk · May 21 10% risk
First fall freeze (32°F)
Oct 5
median: a freeze had happened by this date in half of years
Sep 24 10% chance of a freeze earlier than this
Freeze-free season
151 days
median length between last spring and first fall 32°F freeze
How to read these dates
Spring: a "10% risk" date means NOAA's 1991-2020 data put the chance of a 32°F or colder night after that date at 10%. The "30% risk" date is the convention used by some popular frost calculators (the Old Farmer's Almanac says it uses a 30% probability threshold, source). Fall: a "10%" date means a 10% chance the first freeze comes before it. Source: NOAA readme.
Full table for this station
| Threshold | Spring: latest-freeze date at risk of 10% / 30% / 50% | Fall: first-freeze date at chance of 10% / 50% |
|---|---|---|
| 36°F (frost possible) | Jun 1 / May 26 / May 21 | Sep 15 / Sep 27 |
| 32°F (freeze) | May 21 / May 13 / May 7 | Sep 24 / Oct 5 |
| 28°F (hard freeze) | May 6 / May 1 / Apr 27 | Oct 3 / Oct 19 |
Also at 32°F, last-freeze 70% date May 3 and 90% date Apr 28 (frost still likely after these early dates). Data quality: Standard: 24+ years of qualifying data. Source: NOAA NCEI U.S. Climate Normals 1991-2020, station USC00170480, read 2026-10-17.
Is Memorial Day safe here?
Many New England gardeners wait for Memorial Day (it falls between May 25 and May 31). At this station, NOAA's chance of a 32°F or colder night after May 25 is under 10%, and after May 31 is under 10%. Your own spot may differ. See all stations.
UMaine Extension gives central-Maine planting dates and says to plant 10-14 days earlier on the coast and 10-14 days later in northern Maine (read 2026-10-17).
Your planting schedule
Pick how cautious you want to be. The dates apply UNH Extension's per-crop rules (UNH fact sheet, read 2026-10-17) to this station's last-freeze date. UNH's sheet does not say which probability its "last frost" means, so you choose. These are planning dates, not instructions; follow your seed packet and the weather.
Showing the schedule for the 2027 season (dates repeat yearly). Table below defaults to Typical; it updates when you choose.
| Crop | Start seeds indoors | Outdoors | UNH Extension rule used |
|---|---|---|---|
| Spinach | Feb 18 – Mar 25 | Set out Apr 1 – Apr 22 | Start 4-6 wk before set-out; set out 3-6 wk before last frost. |
| Broccoli | Mar 4 – Apr 1 | Set out Apr 15 – Apr 29 | Start 4-6 wk before set-out; set out 2-4 wk before last frost. |
| Brussels sprout | Mar 4 – Apr 1 | Set out Apr 15 – Apr 29 | Start 4-6 wk before set-out; set out 2-4 wk before last frost. |
| Cabbage | Mar 4 – Mar 18 | Set out Apr 15 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Kale | Mar 4 – Mar 18 | Set out Apr 15 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Kohlrabi | Mar 4 – Mar 18 | Set out Apr 15 | Start 4-6 wk before set-out; set out 4 wk before last frost. |
| Leek | Feb 4 – Feb 18 | Set out Apr 15 | Start 8-10 wk before set-out; set out 4 wk before last frost. |
| Lettuce | Mar 11 – Mar 25 | Set out Apr 15 – Apr 22 | Start 4-5 wk before set-out; set out 3-4 wk before last frost. |
| Onion | Feb 4 – Feb 18 | Set out Apr 15 | Start 8-10 wk before set-out; set out 4 wk before last frost. |
| Radish | — | Sow Apr 15 – Apr 29 | Sow seed in garden 2-4 wk before last frost. |
| Turnip | — | Sow Apr 15 – Apr 29 | Sow seed in garden 2-4 wk before last frost. |
| Parsley | Feb 11 – Feb 25 | Set out Apr 22 – Apr 29 | Start 9-10 wk before set-out; set out 2-3 wk before last frost. |
| Cauliflower | Mar 18 – Apr 1 | Set out Apr 29 | Start 4-6 wk before set-out; set out 2 wk before last frost. |
| Potato | — | Sow Apr 29 – May 6 | Plant seed potatoes 1-2 wk before last frost. |
| Swiss chard | Mar 18 – Apr 1 | Set out Apr 29; or sow Apr 15 | Start 4-6 wk before set-out; set out 2 wk before last frost; or sow seed 4 wk before last frost. |
| Bean | — | Sow on/after May 13 | Sow seed in garden after last frost. |
| Celery | Feb 18 – Mar 4 | Set out on/after May 13 | Start 10-12 wk before set-out; set out after last frost. |
| Parsnip | — | Sow on/after May 13 | Sow seed in garden after last frost. |
| Cucumber | Apr 22 – May 6 | Set out May 20 – May 27 Direct sow when soil reaches 70°F | Start 3-4 wk before set-out; set out 1-2 wk after last frost; or sow when soil warms to 70°F. |
| Sweet potato | — | Plant slips May 20 – May 27 | Plant slips (young plants) 1-2 wk after last frost. |
| Tomato | Mar 25 – Apr 15 | Set out May 20 – May 27 | Start 6-8 wk before set-out; set out 1-2 wk after last frost. |
| Basil | Apr 1 – Apr 15 | Set out May 27 | Start 6-8 wk before set-out; set out 2 wk after last frost. |
| Eggplant | Mar 18 – Apr 8 | Set out May 27 – Jun 3 | Start 8-10 wk before set-out; set out 2-3 wk after last frost. |
| Melon | Apr 29 – May 6 | Set out May 27 | Start 3-4 wk before set-out; set out 2 wk after last frost. |
| Pepper | Mar 18 – Apr 1 | Set out May 27 | Start 8-10 wk before set-out; set out 2 wk after last frost. |
| Pumpkin | Apr 29 – May 6 | Set out May 27 Direct sow when soil reaches 70°F | Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F. |
| Summer squash | Apr 29 – May 6 | Set out May 27 Direct sow when soil reaches 70°F | Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F. |
| Winter squash | Apr 29 – May 6 | Set out May 27 Direct sow when soil reaches 70°F | Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F. |
| Zucchini | Apr 29 – May 6 | Set out May 27 Direct sow when soil reaches 70°F | Start 3-4 wk before set-out; set out 2 wk after last frost; or sow when soil warms to 70°F. |
| Rutabaga | — | Sow Jun 15 – Jul 15 | Sow seed in garden mid-June to mid-July (fixed dates, not tied to frost). |
| Beet | — | Sow when soil reaches 45°F (use a soil thermometer) | Sow seed in garden when soil warms to 45°F. |
| Carrot | — | Sow when soil reaches 60°F (use a soil thermometer) | Sow seed in garden when soil warms to 60°F. |
| Corn | — | Sow when soil reaches 60°F (use a soil thermometer) | Sow seed in garden when soil warms to 60°F. |
| Pea | — | Sow as soon as soil thaws | Sow seed in garden as soon as soil thaws. |
Fall: when the garden ends
At this station the median first 32°F freeze is Oct 5; there is a 10% chance of one before Sep 24. Tender crops (tomatoes, peppers, basil) can be damaged at 33-36°F (Almanac.com notes some plants are damaged in that range); the 36°F first-frost date here is median Sep 27 and 10% date Sep 15. UNH Extension notes many fall vegetables tolerate mild frosts down to about 28°F (median first 28°F here: Oct 19), and that row covers can extend the season. UNH: Fall vegetable gardening, read 2026-10-17.
Your garden is not the weather station
This station sits at 20 ft. UNH Extension says first-freeze dates vary "even between relatively close locations, based on factors such as elevation" (source), and notes that gardeners who keep garden journals can use their own records. Gardeners on Reddit describe the same thing: elevation and cold spots change when they can plant (for example r/vermont). Treat these dates as a starting point.
Nearby stations
- W Rockport 1 NNW, ME: 16 mi away, 361 ft elevation, median last 32°F freeze Apr 27
- Bangor Intl AP, ME: 29 mi away, 148 ft elevation, median last 32°F freeze May 4
- Tenants Harbor, ME: 30 mi away, 21 ft elevation, median last 32°F freeze Apr 27
- Waterville Trtmt Plt, ME: 34 mi away, 73 ft elevation, median last 32°F freeze May 2
- Acadia Np, ME: 36 mi away, 470 ft elevation, median last 32°F freeze Apr 27