First Connecticut Lake, New Hampshire climate: Climate normals at a NOAA weather station
First Connecticut Lake's normal year runs from 0°F January nights to 75°F July afternoons, with 47.1 inches of precipitation and 143 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 3.9°C, January lows of −18°C, July highs of 24°C, 1,197 mm of precipitation a year.
- NOAA stationFirst Connecticut Lake
- Station IDUSC00272999
- Location45.09°N 71.29°W
- Elevation1,650 ft (503 m)
On October 22, the normal high in First Connecticut Lake is 50°F and the normal low 32°F, and the chance of measurable rain or snow is 52%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for First Connecticut Lake.
- Jan 22° 0°
- Feb 25° 0°
- Mar 34° 10°
- Apr 47° 26°
- May 62° 38°
- Jun 70° 48°
- Jul 75° 53°
- Aug 74° 52°
- Sep 66° 44°
- Oct 53° 34°
- Nov 40° 24°
- Dec 29° 11°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at First Connecticut Lake each month?
July is the warmest month, with normal highs of 75°F; January the coldest, with normal lows of 0°F. The most precipitation falls in June (5.14 in), the least in February (2.37 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 22°F | 0°F | 11.1°F | 3.02 | 30.3 | 18 | <1 | 31 | 9 h 10 min |
| February | 25°F | 0°F | 12.8°F | 2.37 | 28.4 | 15 | <1 | 28 | 10 h 20 min |
| March | 34°F | 10°F | 21.9°F | 3.04 | 24.6 | 15 | <1 | 30 | 11 h 50 min |
| April | 47°F | 26°F | 36.3°F | 3.60 | 9.7 | 15 | <1 | 24 | 13 h 30 min |
| May | 62°F | 38°F | 49.9°F | 4.47 | 1.0 | 15 | <1 | 9 | 14 h 50 min |
| June | 70°F | 48°F | 59.3°F | 5.14 | 0.0 | 15 | <1 | 1 | 15 h 40 min |
| July | 75°F | 53°F | 64.2°F | 4.91 | 0.0 | 15 | <1 | <1 | 15 h 20 min |
| August | 74°F | 52°F | 62.7°F | 4.76 | 0.0 | 14 | <1 | <1 | 14 h 10 min |
| September | 66°F | 44°F | 55.1°F | 4.00 | 0.0 | 12 | <1 | 4 | 12 h 40 min |
| October | 53°F | 34°F | 43.5°F | 4.63 | 2.5 | 16 | <1 | 16 | 11 h |
| November | 40°F | 24°F | 31.8°F | 3.62 | 14.6 | 17 | <1 | 25 | 9 h 40 min |
| December | 29°F | 11°F | 19.9°F | 3.57 | 31.9 | 19 | <1 | 30 | 8 h 50 min |
| Year (annual) | 50°F | 28°F | 39.0°F | 47.13 | 143.0 | 185 | <1 | 198 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −5°C | −18°C | −11.6°C | 77 mm | 77 cm |
| February | −4°C | −18°C | −10.7°C | 60 mm | 72 cm |
| March | 1°C | −12°C | −5.6°C | 77 mm | 62 cm |
| April | 8°C | −4°C | 2.4°C | 91 mm | 25 cm |
| May | 16°C | 3°C | 9.9°C | 114 mm | 3 cm |
| June | 21°C | 9°C | 15.2°C | 131 mm | 0 cm |
| July | 24°C | 12°C | 17.9°C | 125 mm | 0 cm |
| August | 23°C | 11°C | 17.1°C | 121 mm | 0 cm |
| September | 19°C | 7°C | 12.8°C | 102 mm | 0 cm |
| October | 12°C | 1°C | 6.4°C | 118 mm | 6 cm |
| November | 4°C | −5°C | −0.1°C | 92 mm | 37 cm |
| December | −2°C | −12°C | −6.7°C | 91 mm | 81 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00272999; 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.
Which months are mildest at First Connecticut Lake?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, September has the fewest days with rain (12).
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 USC00272999.
When is the last frost at First Connecticut Lake?
In First Connecticut Lake, the last spring frost (32°F) comes after May 25 in half of years and after June 8 in one year in ten; the first autumn frost comes before September 24 in half of years and before September 9 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
- May 251 year in 10 after June 8; 9 in 10 after May 9
- First autumn frost, half of years before
- September 241 year in 10 before September 9; 9 in 10 before October 7
NOAA puts the median frost-free season at 121 days, and the season without a hard freeze (28°F) at 148 days.
A hard freeze (28°F) comes after May 9 in half of springs and before October 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts First Connecticut Lake in zone 4a in ZIP code 03592, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 3b: the coldest night of a typical year reaches −30°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in New Hampshire · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00272999; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 at First Connecticut Lake?
In a normal year in First Connecticut Lake, a 90°F day is rare, 198 nights fall to 32°F or colder and 185 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 198a normal year
- Days that stay below freezing
- 93high of 32°F or less
- Days with 0.01 inch of precipitation
- 185a normal year
- Days with 1 inch of snow or more
- 52a normal year
The highest temperature in this station's record (since 1918) is 93°F, on July 8, 1921; the lowest is −45°F, on February 1, 1920.
The wettest calendar year on that record is 1990, with 59.77 in; the snowiest season is 1970–71, with 261.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00272999; records: ACIS (NOAA Regional Climate Centers), station USC00272999. Records use complete months only; a month missing more than three days is left out.
How sunny is it at First Connecticut Lake?
Over a year 66% of the sunlight that would reach the ground under clear skies gets through the clouds at First Connecticut Lake, 3.4 kWh per square metre a day. September is the sunniest month (72%) and December the cloudiest (51%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.4 |
| February | 62% | 2.2 |
| March | 65% | 3.4 |
| April | 65% | 4.4 |
| May | 64% | 5.0 |
| June | 67% | 5.5 |
| July | 71% | 5.5 |
| August | 72% | 4.9 |
| September | 72% | 3.9 |
| October | 60% | 2.3 |
| November | 56% | 1.4 |
| December | 51% | 1.0 |
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 many heating and cooling degree days does First Connecticut Lake record?
A normal year at First Connecticut Lake brings 9,567 heating degree days, 78% more than the median U.S. place (5,373), and 143 cooling degree days, 84% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,470 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,672 | 0 |
| February | 1,462 | 0 |
| March | 1,336 | 0 |
| April | 861 | 0 |
| May | 472 | 4 |
| June | 195 | 26 |
| July | 84 | 59 |
| August | 114 | 41 |
| September | 308 | 12 |
| October | 668 | 0 |
| November | 996 | 0 |
| December | 1,398 | 0 |
| Year (annual) | 9,567 | 143 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00272999. 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.
Have recent years at First Connecticut Lake been warmer than normal?
2025 averaged 39.4°F, 0.4°F above the 1991-2020 normal of 39.0°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 41.4°F | +2.4°F | 38.96 | 123.3 |
| 2022 | 40.8°F | +1.8°F | 53.96 | 118.2 |
| 2023 | 42.1°F | +3.1°F | 53.87 | 109.6 |
| 2024 | 42.7°F | +3.7°F | 51.86 | 139.7 |
| 2025 | 39.4°F | +0.4°F | – | – |
Over 90 complete years from 1921 to 2025, the station's annual mean temperature rose at a fitted 3.9°F per century (+0.21°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00272999; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does First Connecticut Lake's climate compare?
First Connecticut Lake is warmer than 0 of the 28 places with their own NOAA record in New Hampshire, and wetter than 22. Across the 7,247 U.S. stations with normals, its annual mean of 39.0°F is warmer than 4%.
In the Köppen classification computed from these normals, First Connecticut Lake is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about First Connecticut Lake's climate
What is the coldest month at First Connecticut Lake?
January, with a normal high of 22°F and a normal low of 0°F. The warmest is July (75°F by day, 53°F at night).
Does it snow at First Connecticut Lake?
Yes: 143 inches in a normal year, falling on 74 days with 0.1 inch or more, the most in December (31.9 inches).
What is the rainiest month at First Connecticut Lake?
June, with 5.14 in of precipitation in a normal year; the driest is February with 2.37 in.
What plant hardiness zone is First Connecticut Lake in?
The USDA's 2023 map puts First Connecticut Lake in zone 4a in ZIP code 03592, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −30°F (30 years, 1991-2020): zone 3b.
How late can frost come at First Connecticut Lake?
In half of years the last 32°F night comes after May 25; in one year in ten it comes after June 8. Waiting until June 8 leaves about a one-in-ten chance of a later frost.
Nearby and next
- New Hampshire climateThe statewide normals and every place in the state
- Colebrook, NH20 miles from this station, 39.7°F a year
- Averill, VT21 miles from this station, 39.1°F a year
- Errol Airport, NH22 miles from this station, 39.5°F a year
- Middle Dam, ME28 miles from this station, 40.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made