USDA Hardiness Zone 7a
Frost Dates for 06335 — Gales Ferry, Connecticut
NOAA 1991–2020 normals from Groton, CT (40 ft), 6 miles south.
Updated
In Gales Ferry, the last spring frost (32°F) is around April 8 in half of years and has passed by April 22 in nine years out of ten. The first fall frost comes around November 2, as early as October 18 one year in ten, leaving a typical freeze-free season of 207 days (NOAA, Groton, CT).
- Last spring frost
- April 8
- First fall frost
- November 2
- Growing season
- 207 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- December 13
- Last snow
- March 14
- Winters with snow
- 100%
- Snow per year
- 24.5"
median, 1991–2020
median, 1991–2020
21 of 21 observed
NOAA normal
Frost risk by date in Gales Ferry
Half of springs at Groton, CT see their last 32°F night by April 8; only one in ten is past it by March 28, and one in ten still has one after April 22. Planting tender crops after April 14 leaves a 30% risk of a frost on them, after April 17 20%, and after April 22 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 28 Connecticut stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 2 in half of years, as early as October 18 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 12 days later, around November 14; in spring the one-in-ten date for 28°F is April 7, 15 days before the 32°F one. The freeze-free season lasts 207 days in a typical year, longer than at 93% of the 28 Connecticut stations; it reaches 226 days one year in ten and falls short of 188 one year in ten. On average 102 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 14 days longer, to about April 22, and return around October 21. Severe cold of 16°F or below comes every winter, usually between December 24 and March 1.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 10 | Apr 14 | Apr 17 | Apr 20 | Apr 22 | Apr 25 | Apr 29 | May 1 | May 5 |
| 32°F | Mar 28 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 17 | Apr 22 |
| 28°F | Mar 14 | Mar 18 | Mar 23 | Mar 26 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 7 |
| 24°F | Mar 4 | Mar 9 | Mar 12 | Mar 15 | Mar 17 | Mar 20 | Mar 23 | Mar 27 | Mar 31 |
| 20°F | Feb 22 | Feb 28 | Mar 4 | Mar 7 | Mar 10 | Mar 12 | Mar 15 | Mar 19 | Mar 24 |
| 16°F | Feb 7 | Feb 15 | Feb 22 | Feb 26 | Mar 1 | Mar 4 | Mar 7 | Mar 10 | Mar 16 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 8 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 31 | Nov 4 |
| 32°F | Oct 18 | Oct 23 | Oct 27 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 11 | Nov 15 |
| 28°F | Nov 1 | Nov 4 | Nov 9 | Nov 12 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Dec 1 |
| 24°F | Nov 13 | Nov 18 | Nov 22 | Nov 26 | Nov 29 | Dec 1 | Dec 4 | Dec 8 | Dec 14 |
| 20°F | Nov 25 | Nov 30 | Dec 3 | Dec 6 | Dec 10 | Dec 14 | Dec 19 | Dec 23 | Dec 28 |
| 16°F | Dec 5 | Dec 12 | Dec 17 | Dec 21 | Dec 24 | Dec 28 | Jan 1 | Jan 6 | Jan 13 |
Freeze probabilities 1991–2020 at Groton, CT, 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 06335 →Compare Gales Ferry with another place →
Weather by month in Gales Ferry
July is the warmest month at Groton, CT, averaging 81°F by day and 66°F at night; January is the coldest at 39°F and 24°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 80% of years.
Warmth for growing adds up to 2,990 growing degree days a year (base 50°F), more than at 61% of the 28 Connecticut stations. 29% of them (853) have built up by the end of June, and July adds the most, 724. Precipitation totals 48.9 inches a year, most in March (4.9") and least in February (3.4"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 39 | 24 | 3.9 | 100% | 26 | 2 |
| Feb | 41 | 25 | 3.4 | 100% | 23 | 1 |
| Mar | 47 | 32 | 4.9 | 100% | 18 | 9 |
| Apr | 57 | 41 | 4.4 | 80% | 4 | 66 |
| May | 66 | 50 | 3.7 | 2% | 0 | 258 |
| Jun | 75 | 59 | 3.9 | 0% | 0 | 518 |
| Jul | 81 | 66 | 3.4 | 0% | 0 | 724 |
| Aug | 80 | 65 | 4.2 | 0% | 0 | 696 |
| Sep | 74 | 58 | 4.3 | 0% | 0 | 475 |
| Oct | 63 | 47 | 4.4 | 43% | 1 | 192 |
| Nov | 53 | 38 | 3.8 | 98% | 10 | 44 |
| Dec | 44 | 30 | 4.6 | 100% | 21 | 7 |
Monthly normals 1991–2020 at Groton, CT (40 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, Norwich Public Utility Plt, CT, 7 miles north of Gales Ferry, has a last frost 6 days later (April 14), a first frost 9 days earlier (October 24), a season 15 days shorter.
When it snows in Gales Ferry, Connecticut
The first measurable snow (0.1 inch or more) in Gales Ferry usually arrives around December 13, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Groton, CT, 5.6 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 25 days after the last snow.
Planting calendar for 06335
| When | What to do |
|---|---|
| January 28 – February 11 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 11 – February 25 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 11 – March 25 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 10 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 2 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 06335 is 6 miles from Groton, CT, which stands at 40 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 06340 (Groton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06335 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Connecticut →
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.