Cornwall, Vermont climate: Climate normals at a NOAA weather station
Cornwall's normal year runs from 9°F January nights to 80°F July afternoons, with 38.7 inches of precipitation and 59 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.2°C, January lows of −13°C, July highs of 27°C, 982 mm of precipitation a year.
- NOAA stationCornwall
- Station IDUSC00431580
- Location43.96°N 73.21°W
- Elevation345 ft (105 m)
On October 22, the normal high in Cornwall is 55°F and the normal low 36°F, and the chance of measurable rain or snow is 38%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Cornwall.
- Jan 27° 9°
- Feb 30° 10°
- Mar 40° 20°
- Apr 54° 33°
- May 67° 45°
- Jun 76° 55°
- Jul 80° 60°
- Aug 79° 57°
- Sep 71° 49°
- Oct 57° 38°
- Nov 44° 28°
- Dec 33° 18°
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 Cornwall each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 9°F. The most precipitation falls in June (4.21 in), the least in February (2.07 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 27°F | 9°F | 18.2°F | 2.55 | 13.3 | 11 | <1 | 29 | 9 h 10 min |
| February | 30°F | 10°F | 20.3°F | 2.07 | 13.3 | 9 | <1 | 27 | 10 h 30 min |
| March | 40°F | 20°F | 29.8°F | 2.42 | 11.9 | 9 | <1 | 26 | 11 h 50 min |
| April | 54°F | 33°F | 43.2°F | 3.35 | 2.6 | 11 | <1 | 15 | 13 h 20 min |
| May | 67°F | 45°F | 56.0°F | 3.37 | 0.0 | 11 | <1 | 2 | 14 h 40 min |
| June | 76°F | 55°F | 65.0°F | 4.21 | 0.0 | 12 | 1 | <1 | 15 h 30 min |
| July | 80°F | 60°F | 70.0°F | 4.09 | 0.0 | 11 | 3 | <1 | 15 h 10 min |
| August | 79°F | 57°F | 67.8°F | 3.53 | 0.0 | 11 | 2 | <1 | 14 h |
| September | 71°F | 49°F | 60.2°F | 3.25 | 0.0 | 9 | 1 | 1 | 12 h 40 min |
| October | 57°F | 38°F | 47.7°F | 3.96 | 0.3 | 12 | <1 | 8 | 11 h 10 min |
| November | 44°F | 28°F | 36.4°F | 2.85 | 3.8 | 10 | <1 | 19 | 9 h 40 min |
| December | 33°F | 18°F | 25.3°F | 3.02 | 13.4 | 12 | <1 | 28 | 9 h |
| Year (annual) | 55°F | 35°F | 45.0°F | 38.67 | 58.6 | 129 | 7 | 155 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −13°C | −7.7°C | 65 mm | 34 cm |
| February | −1°C | −12°C | −6.5°C | 53 mm | 34 cm |
| March | 4°C | −7°C | −1.2°C | 61 mm | 30 cm |
| April | 12°C | 0°C | 6.2°C | 85 mm | 7 cm |
| May | 19°C | 7°C | 13.3°C | 86 mm | 0 cm |
| June | 24°C | 13°C | 18.3°C | 107 mm | 0 cm |
| July | 27°C | 15°C | 21.1°C | 104 mm | 0 cm |
| August | 26°C | 14°C | 19.9°C | 90 mm | 0 cm |
| September | 22°C | 10°C | 15.7°C | 83 mm | 0 cm |
| October | 14°C | 3°C | 8.7°C | 101 mm | 1 cm |
| November | 7°C | −2°C | 2.4°C | 72 mm | 10 cm |
| December | 1°C | −8°C | −3.7°C | 77 mm | 34 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00431580; 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 Cornwall?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (9).
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 USC00431580.
When is the last frost at Cornwall?
In Cornwall, the last spring frost (32°F) comes after May 5 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 3 in half of years and before September 21 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 51 year in 10 after May 20; 9 in 10 after April 23
- First autumn frost, half of years before
- October 31 year in 10 before September 21; 9 in 10 before October 19
NOAA puts the median frost-free season at 151 days, and the season without a hard freeze (28°F) at 173 days.
A hard freeze (28°F) comes after April 26 in half of springs and before October 16 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Cornwall in zone 5a in ZIP code 05753, 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 5a: the coldest night of a typical year reaches −17°F (24 complete years).
Frost dates for every NOAA station in Vermont · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00431580; 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 Cornwall?
In a normal year in Cornwall, 7 days a year reach 90°F, 155 nights fall to 32°F or colder and 129 days bring measurable precipitation.
- Days at 90°F or more
- 7a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 155a normal year
- Days that stay below freezing
- 57high of 32°F or less
- Days with 0.01 inch of precipitation
- 129a normal year
- Days with 1 inch of snow or more
- 17a normal year
The highest temperature in this station's record (since 1894) is 104°F, on August 21, 1916; the lowest is −32°F, on December 30, 1933.
The wettest calendar year on that record is 2008, with 51.11 in; the snowiest season is 1971–72, with 124.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00431580; records: ACIS (NOAA Regional Climate Centers), station USC00431580. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Cornwall?
Over a year 69% of the sunlight that would reach the ground under clear skies gets through the clouds at Cornwall, 3.6 kWh per square metre a day. August is the sunniest month (77%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.5 |
| February | 64% | 2.4 |
| March | 66% | 3.5 |
| April | 67% | 4.6 |
| May | 68% | 5.3 |
| June | 70% | 5.7 |
| July | 76% | 5.9 |
| August | 77% | 5.2 |
| September | 76% | 4.2 |
| October | 64% | 2.6 |
| November | 64% | 1.7 |
| December | 56% | 1.2 |
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 Cornwall record?
A normal year at Cornwall brings 7,705 heating degree days, 43% more than the median U.S. place (5,373), and 446 cooling degree days, 51% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,295 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,452 | 0 |
| February | 1,252 | 0 |
| March | 1,091 | 0 |
| April | 658 | 2 |
| May | 300 | 21 |
| June | 83 | 83 |
| July | 16 | 171 |
| August | 37 | 124 |
| September | 186 | 42 |
| October | 538 | 2 |
| November | 860 | 0 |
| December | 1,232 | 0 |
| Year (annual) | 7,705 | 446 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00431580. 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 Cornwall been warmer than normal?
2025 averaged 45.9°F, 0.9°F above the 1991-2020 normal of 45.0°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 46.8°F | +1.8°F | 37.51 | 53.9 |
| 2022 | 45.2°F | +0.2°F | 34.56 | 73.2 |
| 2023 | 47.3°F | +2.3°F | – | 48.0 |
| 2024 | 48.2°F | +3.2°F | 39.61 | 64.1 |
| 2025 | 45.9°F | +0.9°F | – | 67.8 |
Over 82 complete years from 1895 to 2025, the station's annual mean temperature rose at a fitted 2.7°F per century (+0.15°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00431580; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Cornwall's climate compare?
Cornwall is warmer than 19 of the 29 places with their own NOAA record in Vermont, and wetter than 5. Across the 7,247 U.S. stations with normals, its annual mean of 45.0°F is warmer than 19%.
In the Köppen classification computed from these normals, Cornwall 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.
Which places near Cornwall share this climate record?
3 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.
- Middlebury, VT9,214 people · 4 mi NE
- Ticonderoga, NY3,375 people · 13 mi SW
- Schroon Lake, NY898 people · 29 mi W
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 Cornwall's climate
What is the coldest month at Cornwall?
January, with a normal high of 27°F and a normal low of 9°F. The warmest is July (80°F by day, 60°F at night).
Does it snow at Cornwall?
Yes: 59 inches in a normal year, falling on 28 days with 0.1 inch or more, the most in December (13.4 inches).
What is the rainiest month at Cornwall?
June, with 4.21 in of precipitation in a normal year; the driest is February with 2.07 in.
What plant hardiness zone is Cornwall in?
The USDA's 2023 map puts Cornwall in zone 5a in ZIP code 05753, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −17°F (24 years, 1991-2020): zone 5a.
How late can frost come at Cornwall?
In half of years the last 32°F night comes after May 5; in one year in ten it comes after May 20. Waiting until May 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Vermont climateThe statewide normals and every place in the state
- Salisbury (2 mi N), VT6 miles from this station, 45.9°F a year
- South Lincoln, VT14 miles from this station, 41.2°F a year
- Vergennes, VT15 miles from this station, 46.3°F a year
- Rochester, VT21 miles from this station, 44.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made