Setauket, New York climate: Normal weather by month, frost dates and records
Setauket's normal year runs from 26°F January nights to 83°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.9°C, January lows of −3°C, July highs of 28°C.
- NOAA stationSetauket Strong
- Station IDUSC00307633
- Location40.96°N 73.10°W
- Elevation40 ft (12 m)
- From the centerunder 1 mile
- Population (census place)3,687
On October 14, the normal high in Setauket is 64°F and the normal low 49°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Setauket.
- Jan 40° 26°
- Feb 41° 26°
- Mar 48° 32°
- Apr 60° 41°
- May 69° 50°
- Jun 78° 60°
- Jul 83° 66°
- Aug 82° 65°
- Sep 75° 60°
- Oct 64° 49°
- Nov 53° 39°
- Dec 45° 31°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Setauket each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 26°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 40°F | 26°F | 32.7°F | – | <1 | 25 | 9 h 30 min |
| February | 41°F | 26°F | 33.5°F | – | <1 | 22 | 10 h 40 min |
| March | 48°F | 32°F | 40.1°F | – | <1 | 18 | 11 h 50 min |
| April | 60°F | 41°F | 50.2°F | – | <1 | 5 | 13 h 20 min |
| May | 69°F | 50°F | 59.5°F | – | 1 | 1 | 14 h 30 min |
| June | 78°F | 60°F | 68.9°F | – | 3 | <1 | 15 h 10 min |
| July | 83°F | 66°F | 74.4°F | – | 7 | <1 | 14 h 50 min |
| August | 82°F | 65°F | 73.7°F | – | 4 | <1 | 13 h 50 min |
| September | 75°F | 60°F | 67.4°F | – | 1 | <1 | 12 h 30 min |
| October | 64°F | 49°F | 56.2°F | – | <1 | <1 | 11 h 10 min |
| November | 53°F | 39°F | 46.3°F | – | <1 | 8 | 10 h |
| December | 45°F | 31°F | 37.9°F | – | <1 | 19 | 9 h 20 min |
| Year (annual) | 62°F | 45°F | 53.4°F | – | 17 | 96 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 4°C | −3°C | 0.4°C |
| February | 5°C | −3°C | 0.8°C |
| March | 9°C | 0°C | 4.5°C |
| April | 15°C | 5°C | 10.1°C |
| May | 21°C | 10°C | 15.3°C |
| June | 26°C | 16°C | 20.5°C |
| July | 28°C | 19°C | 23.6°C |
| August | 28°C | 18°C | 23.2°C |
| September | 24°C | 15°C | 19.7°C |
| October | 18°C | 9°C | 13.4°C |
| November | 12°C | 4°C | 7.9°C |
| December | 7°C | 0°C | 3.3°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Islip (11 miles away), gets 32 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00307633; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Setauket?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00307633.
When is the last frost in Setauket?
In Setauket, the last spring frost (32°F) comes after April 15 in half of years and after May 4 in one year in ten; the first autumn frost comes before November 10 in half of years and before October 27 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 151 year in 10 after May 4; 9 in 10 after April 1
- First autumn frost, half of years before
- November 101 year in 10 before October 27; 9 in 10 before November 24
NOAA puts the median frost-free season at 208 days, and the season without a hard freeze (28°F) at 235 days.
A hard freeze (28°F) comes after March 31 in half of springs and before November 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Setauket in zone 7b in ZIP code 11733.
Frost dates for every NOAA station in New York · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00307633; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Setauket?
In a normal year in Setauket, 17 days a year reach 90°F and 96 nights fall to 32°F or colder.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 96a normal year
- Days that stay below freezing
- 11high of 32°F or less
The highest temperature in this station's record (since 1885) is 100°F, on July 6, 2010; the lowest is −11°F, on February 9, 1934.
The wettest calendar year on that record is 1983, with 59.39 in; the snowiest season is 1947–48, with 78.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00307633; records: ACIS (NOAA Regional Climate Centers), station USC00307633. Records use complete months only; a month missing more than three days is left out.
How sunny is Setauket?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Setauket, 4.0 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.9 |
| February | 70% | 2.8 |
| March | 71% | 3.8 |
| April | 73% | 5.0 |
| May | 73% | 5.6 |
| June | 78% | 6.1 |
| July | 82% | 6.2 |
| August | 81% | 5.5 |
| September | 79% | 4.5 |
| October | 72% | 3.0 |
| November | 72% | 2.1 |
| December | 66% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Setauket need?
A normal year in Setauket brings 5,062 heating degree days, 6% fewer than the median U.S. place (5,373), and 867 cooling degree days, 4% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,245 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,000 | 0 |
| February | 881 | 0 |
| March | 772 | 0 |
| April | 448 | 3 |
| May | 201 | 30 |
| June | 30 | 147 |
| July | 1 | 294 |
| August | 2 | 270 |
| September | 43 | 115 |
| October | 282 | 8 |
| November | 561 | 0 |
| December | 842 | 0 |
| Year (annual) | 5,062 | 867 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00307633. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Setauket's climate compare?
Setauket is warmer than 122 of the other 130 places with their own NOAA record in New York. Across the 7,247 U.S. stations with normals, its annual mean of 53.4°F is warmer than 55%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Setauket share this climate record?
15 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- St. James, NY13,680 people · 6 mi SW
- Stony Brook, NY12,827 people · 4 mi S
- East Setauket, NY10,385 people · 3 mi S
- Stony Brook University, NY9,138 people · 3 mi S
- Staples, CT6,985 people · 18 mi NW
- Coleytown, CT3,479 people · 20 mi NW
- Greens Farms, CT3,022 people · 16 mi NW
- Fairfield University, CT2,516 people · 16 mi NW
- Mill Plain, CT1,980 people · 16 mi NW
- Nissequogue, NY1,625 people · 6 mi SW
- Southport, CT1,529 people · 15 mi NW
- Head of the Harbor, NY1,475 people · 5 mi SW
- Poquott, NY929 people · 1 mi SE
- Old Field, NY925 people · 1 mi W
- Belle Terre, NY788 people · 2 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Setauket's climate
What is the coldest month in Setauket?
January, with a normal high of 40°F and a normal low of 26°F. The warmest is July (83°F by day, 66°F at night).
Does it snow in Setauket?
Yes. NOAA publishes no 1991-2020 snowfall normal for Setauket's NOAA station; the nearest record that keeps one, Islip (11 miles away), records 32 inches of snow in a normal year.
What plant hardiness zone is Setauket in?
The USDA's 2023 map puts Setauket in zone 7b in ZIP code 11733.
How late can frost come in Setauket?
In half of years the last 32°F night comes after April 15; in one year in ten it comes after May 4. Waiting until May 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- New York climateThe statewide normals and every place in the state
- Mount Sinai, NY5 miles from this station, 54.7°F a year
- Islip, NY11 miles from this station, 53.1°F a year
- Bridgeport, CT14 miles from this station, 53.4°F a year
- Upton Cooperative - Weather Office New York, NY14 miles from this station, 51.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made