USDA Hardiness Zone 5b
Frost Dates for 04614 — Blue Hill, Maine
NOAA 1991–2020 normals from E Surry, ME (105 ft), 8 miles northeast.
Updated
In Blue Hill, 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 9, as early as September 27 one year in ten, leaving a typical freeze-free season of 152 days (NOAA, E Surry, ME).
- Last spring frost
- May 8
- First fall frost
- October 9
- Growing season
- 152 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- November 28
- Last snow
- April 2
- Winters with snow
- 95%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
19 of 20 observed
NOAA normal
Frost risk by date in Blue Hill
Half of springs at E Surry, 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 15 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 9 in half of years, as early as September 27 one year in ten, and holds off past October 24 one year in ten. A hard freeze of 28°F follows 12 days later, around October 21; in spring the one-in-ten date for 28°F is May 10, 13 days before the 32°F one. The freeze-free season lasts 152 days in a typical year, longer than at 54% of the 52 Maine stations; it reaches 171 days one year in ten and falls short of 132 one year in ten. On average 162 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 28. Severe cold of 16°F or below comes every winter, usually between November 26 and March 26.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 8 | May 13 | May 16 | May 19 | May 21 | May 24 | May 27 | May 29 | Jun 3 |
| 32°F | Apr 27 | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 15 | May 18 | May 23 |
| 28°F | Apr 12 | Apr 17 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 5 | May 10 |
| 24°F | Mar 31 | Apr 3 | Apr 6 | Apr 8 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 24 |
| 20°F | Mar 19 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 6 | Apr 8 | Apr 13 |
| 16°F | Mar 11 | Mar 15 | Mar 19 | Mar 23 | Mar 26 | Mar 29 | Mar 31 | Apr 3 | Apr 5 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 10 |
| 32°F | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 24 |
| 28°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 6 |
| 24°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 18 |
| 20°F | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 29 |
| 16°F | Nov 13 | Nov 16 | Nov 20 | Nov 23 | Nov 26 | Nov 28 | Nov 30 | Dec 3 | Dec 8 |
Freeze probabilities 1991–2020 at E Surry, 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 04614 →Compare Blue Hill with another place →
Compared with the next station
The nearest other station, Acadia Np, ME, 16 miles east of Blue Hill and 365 feet higher, has a last frost 11 days earlier (April 27), a first frost 13 days later (October 22), a season 25 days longer.
When it snows in Blue Hill, Maine
The first measurable snow (0.1 inch or more) in Blue Hill usually arrives around November 28, and the last of the season around April 2. Those are the middle dates across the winters of 1991–2020 at Acadia Np, ME, 16.1 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 36 days after the last snow.
Planting calendar for 04614
| 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 17 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 25 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 9 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 04614 is 8 miles from E Surry, ME, which stands at 105 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 04605 (Ellsworth). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04614 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°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.