USDA Hardiness Zone 5b
Frost Dates for 04015 — Casco, Maine
NOAA 1991–2020 normals from Windham 2NW, ME (443 ft), 7 miles south.
Updated
In Casco, the last spring frost (32°F) is around April 30 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 20, as early as October 5 one year in ten, leaving a typical freeze-free season of 172 days (NOAA, Windham 2NW, ME).
- Last spring frost
- April 30
- First fall frost
- October 20
- Growing season
- 172 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 13
- Last snow
- April 8
- Winters with snow
- 100%
- Snow per year
- 80.1"
median, 1991–2020
median, 1991–2020
23 of 23 observed
NOAA normal
Frost risk by date in Casco
Half of springs at Windham 2NW, ME see their last 32°F night by April 30; only one in ten is past it by April 18, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 52 Maine stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 20 in half of years, as early as October 5 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 12 days later, around November 1; in spring the one-in-ten date for 28°F is April 29, 13 days before the 32°F one. The freeze-free season lasts 172 days in a typical year, longer than at 85% of the 52 Maine stations; it reaches 190 days one year in ten and falls short of 153 one year in ten. On average 147 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 11 days longer, to about May 11, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 1 and March 21.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | May 2 | May 5 | May 8 | May 11 | May 13 | May 15 | May 19 | May 22 |
| 32°F | Apr 18 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 1 | May 4 | May 7 | May 12 |
| 28°F | Apr 5 | Apr 9 | Apr 12 | Apr 15 | Apr 17 | Apr 19 | Apr 22 | Apr 24 | Apr 29 |
| 24°F | Mar 26 | Mar 31 | Apr 2 | Apr 4 | Apr 5 | Apr 7 | Apr 9 | Apr 13 | Apr 18 |
| 20°F | Mar 16 | Mar 20 | Mar 23 | Mar 28 | Mar 30 | Apr 1 | Apr 3 | Apr 5 | Apr 8 |
| 16°F | Mar 10 | Mar 13 | Mar 16 | Mar 19 | Mar 21 | Mar 24 | Mar 28 | Mar 31 | Apr 2 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 23 |
| 32°F | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 20 | Oct 22 | Oct 26 | Oct 30 | Nov 3 |
| 28°F | Oct 17 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 16 |
| 24°F | Nov 1 | Nov 4 | Nov 8 | Nov 11 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 27 |
| 20°F | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 24 | Nov 27 | Nov 30 | Dec 3 | Dec 9 |
| 16°F | Nov 18 | Nov 24 | Nov 27 | Nov 30 | Dec 1 | Dec 5 | Dec 8 | Dec 12 | Dec 17 |
Freeze probabilities 1991–2020 at Windham 2NW, 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 04015 →Compare Casco with another place →
Compared with the next station
The nearest other station, Poland, ME, 8 miles northeast of Casco, has a last frost 3 days later (May 3), a first frost 13 days earlier (October 7), a season 15 days shorter.
When it snows in Casco, Maine
The first measurable snow (0.1 inch or more) in Casco usually arrives around November 13, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Poland, ME, 8.5 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 22 days after the last snow.
Planting calendar for 04015
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 28 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 6 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 20 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 04015 is 7 miles from Windham 2NW, ME, which stands at 443 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 04062 (Windham). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04015 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.