USDA Hardiness Zone 5a
Frost Dates for 04427 — Corinth, Maine
NOAA 1991–2020 normals from Corinna, ME (297 ft), 12 miles west.
Updated
In Corinth, the last spring frost (32°F) is around May 8 in half of years and has passed by May 23 in nine years out of ten. The first fall frost comes around October 3, as early as September 21 one year in ten, leaving a typical freeze-free season of 148 days (NOAA, Corinna, ME).
- Last spring frost
- May 8
- First fall frost
- October 3
- Growing season
- 148 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 23
- Last snow
- April 5
- Winters with snow
- 100%
- Snow per year
- 71.5"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Corinth
Half of springs at Corinna, ME see their last 32°F night by May 8; only one in ten is past it by April 27, and one in ten still has one after May 23. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 18 20%, and after May 23 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 83% of the 52 Maine stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 3 in half of years, as early as September 21 one year in ten, and holds off past October 17 one year in ten. A hard freeze of 28°F follows 12 days later, around October 15; in spring the one-in-ten date for 28°F is May 8, 15 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 58% of the 52 Maine stations; it reaches 164 days one year in ten and falls short of 129 one year in ten. On average 175 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 13 days longer, to about May 21, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 22 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 8 | May 12 | May 15 | May 19 | May 21 | May 24 | May 27 | May 30 | Jun 3 |
| 32°F | Apr 27 | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 14 | May 18 | May 23 |
| 28°F | Apr 13 | Apr 18 | Apr 21 | Apr 24 | Apr 26 | Apr 29 | May 1 | May 3 | May 8 |
| 24°F | Apr 2 | Apr 6 | Apr 8 | Apr 11 | Apr 14 | Apr 16 | Apr 19 | Apr 22 | Apr 25 |
| 20°F | Mar 24 | Mar 30 | Apr 2 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 13 | Apr 17 |
| 16°F | Mar 16 | Mar 21 | Mar 26 | Mar 29 | Mar 31 | Apr 1 | Apr 3 | Apr 6 | Apr 9 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 10 | Sep 15 | Sep 18 | Sep 21 | Sep 23 | Sep 25 | Sep 28 | Oct 1 | Oct 5 |
| 32°F | Sep 21 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 17 |
| 28°F | Oct 1 | Oct 4 | Oct 8 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 26 | Nov 1 |
| 24°F | Oct 13 | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 14 |
| 20°F | Oct 29 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 26 |
| 16°F | Nov 8 | Nov 12 | Nov 15 | Nov 19 | Nov 22 | Nov 24 | Nov 27 | Nov 30 | Dec 4 |
Freeze probabilities 1991–2020 at Corinna, ME, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 04427 →Compare Corinth with another place →
Weather by month in Corinth
July is the warmest month at Corinna, ME, averaging 81°F by day and 58°F at night; January is the coldest at 28°F and 6°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 78% of years.
Warmth for growing adds up to 2,146 growing degree days a year (base 50°F), more than at 69% of the 52 Maine stations. 29% of them (622) have built up by the end of June, and July adds the most, 597. Precipitation totals 44.6 inches a year, most in October (4.8") and least in February (2.8"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 28 | 6 | 3.4 | 100% | 30 | 0 |
| Feb | 32 | 7 | 2.8 | 100% | 27 | 0 |
| Mar | 41 | 18 | 3.4 | 100% | 28 | 2 |
| Apr | 54 | 31 | 3.8 | 100% | 19 | 26 |
| May | 67 | 43 | 3.6 | 78% | 4 | 181 |
| Jun | 75 | 52 | 4.0 | 3% | 0 | 414 |
| Jul | 81 | 58 | 3.2 | 0% | 0 | 597 |
| Aug | 80 | 56 | 3.6 | 0% | 0 | 549 |
| Sep | 72 | 48 | 3.6 | 34% | 2 | 303 |
| Oct | 59 | 37 | 4.8 | 98% | 12 | 68 |
| Nov | 46 | 27 | 4.1 | 100% | 23 | 7 |
| Dec | 34 | 16 | 4.3 | 100% | 29 | 0 |
Monthly normals 1991–2020 at Corinna, ME (297 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Old Town 2 W, ME, 15 miles east of Corinth and 170 feet lower, has a last frost 5 days later (May 13), a first frost 5 days earlier (September 28), a season 11 days shorter.
When it snows in Corinth, Maine
The first measurable snow (0.1 inch or more) in Corinth usually arrives around November 23, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Corinna, ME, 12.2 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 33 days after the last snow.
Planting calendar for 04427
| When | What to do |
|---|---|
| February 27 – March 13 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 13 – March 27 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 10 – April 24 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 3 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 04427 is 12 miles from Corinna, ME, which stands at 297 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 04930 (Dexter). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04427 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.