USDA Hardiness Zone 7b
Frost Dates for 11733 — East Setauket, New York
NOAA 1991–2020 normals from Setauket Strong, NY (40 ft), 2 miles north.
Updated
In East Setauket, the last spring frost (32°F) is around April 15 in half of years and has passed by May 4 in nine years out of ten. The first fall frost comes around November 10, as early as October 27 one year in ten, leaving a typical freeze-free season of 208 days (NOAA, Setauket Strong, NY).
- Last spring frost
- April 15
- First fall frost
- November 10
- Growing season
- 208 days
- Hardiness zone
- 7b
50% probability
50% probability
freeze-free, 50%
5 to 10°F (-15.0 to -12.2°C) coldest night
- First snow
- December 11
- Last snow
- March 20
- Winters with snow
- 100%
- Snow per year
- 31.8"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in East Setauket
Half of springs at Setauket Strong, NY see their last 32°F night by April 15; only one in ten is past it by April 1, and one in ten still has one after May 4. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 29 20%, and after May 4 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 98% of the 173 New York stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 10 in half of years, as early as October 27 one year in ten, and holds off past November 24 one year in ten. A hard freeze of 28°F follows 11 days later, around November 21; in spring the one-in-ten date for 28°F is April 19, 15 days before the 32°F one. The freeze-free season lasts 208 days in a typical year, longer than at 91% of the 173 New York stations; it reaches 230 days one year in ten and falls short of 185 one year in ten. On average 96 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 15 days longer, to about April 30, and return around October 29. Severe cold of 16°F or below comes in 99% of winters, usually between December 30 and February 24.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Apr 19 | Apr 23 | Apr 26 | Apr 30 | May 3 | May 6 | May 10 | May 15 |
| 32°F | Apr 1 | Apr 5 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 23 | Apr 29 | May 4 |
| 28°F | Mar 14 | Mar 21 | Mar 26 | Mar 29 | Mar 31 | Apr 3 | Apr 5 | Apr 9 | Apr 19 |
| 24°F | Mar 2 | Mar 8 | Mar 12 | Mar 15 | Mar 18 | Mar 22 | Mar 27 | Mar 30 | Apr 3 |
| 20°F | Feb 18 | Feb 25 | Feb 28 | Mar 4 | Mar 6 | Mar 10 | Mar 13 | Mar 16 | Mar 23 |
| 16°F99% of yrs | Feb 1 | Feb 9 | Feb 15 | Feb 19 | Feb 24 | Feb 28 | Mar 3 | Mar 6 | Mar 12 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 14 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
| 32°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 12 | Nov 15 | Nov 19 | Nov 24 |
| 28°F | Nov 9 | Nov 13 | Nov 16 | Nov 19 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 5 |
| 24°F | Nov 18 | Nov 23 | Nov 28 | Dec 1 | Dec 3 | Dec 6 | Dec 9 | Dec 15 | Dec 21 |
| 20°F | Dec 1 | Dec 4 | Dec 8 | Dec 11 | Dec 15 | Dec 20 | Dec 23 | Dec 29 | Jan 5 |
| 16°F99% of yrs | Dec 7 | Dec 14 | Dec 21 | Dec 25 | Dec 30 | Jan 3 | Jan 8 | Jan 14 | Jan 24 |
Freeze probabilities 1991–2020 at Setauket Strong, NY, 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 11733 →Compare East Setauket with another place →
Weather by month in East Setauket
July is the warmest month at Setauket Strong, NY, averaging 83°F by day and 66°F at night; January is the coldest at 40°F and 26°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 89% of years and May still brings one in 17% of years.
Warmth for growing adds up to 3,245 growing degree days a year (base 50°F), more than at 92% of the 173 New York stations. 30% of them (970) have built up by the end of June, and July adds the most, 758.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 40 | 26 | 100% | 25 | 2 |
| Feb | 41 | 26 | 100% | 22 | 1 |
| Mar | 48 | 32 | 100% | 18 | 11 |
| Apr | 60 | 41 | 89% | 5 | 90 |
| May | 69 | 50 | 17% | 1 | 299 |
| Jun | 78 | 60 | 0% | 0 | 567 |
| Jul | 83 | 66 | 0% | 0 | 758 |
| Aug | 82 | 65 | 0% | 0 | 733 |
| Sep | 75 | 60 | 0% | 0 | 522 |
| Oct | 64 | 49 | 18% | <1 | 209 |
| Nov | 53 | 39 | 96% | 8 | 46 |
| Dec | 45 | 31 | 100% | 19 | 7 |
Monthly normals 1991–2020 at Setauket Strong, NY (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, Mt Sinai, NY, 5 miles east of East Setauket, has a last frost 11 days earlier (April 4), a first frost 3 days earlier (November 7), a season 7 days longer.
When it snows in East Setauket, New York
The first measurable snow (0.1 inch or more) in East Setauket usually arrives around December 11, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Islip Li Macarthur Airport, NY, 9.5 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 26 days after the last snow.
Planting calendar for 11733
| When | What to do |
|---|---|
| February 4 – February 18 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 18 – March 4 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 18 – April 1 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 15 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 10 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 11733 is 2 miles from Setauket Strong, NY, 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 11790 (Stony Brook). The 2023 USDA Plant Hardiness Zone Map lists ZIP 11733 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°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.