Norwich, Connecticut climate: Normal weather by month, frost dates and records
Norwich's normal year runs from 21°F January nights to 84°F July afternoons, with 52.2 inches of precipitation and 28 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.0°C, January lows of −6°C, July highs of 29°C, 1,325 mm of precipitation a year.
- NOAA stationNorwich Public Utility Plant
- Station IDUSC00065910
- Location41.53°N 72.07°W
- Elevation20 ft (6 m)
- From the center2 miles
- Population39,993
On October 14, the normal high in Norwich is 65°F and the normal low 44°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Norwich.
- Jan 38° 21°
- Feb 41° 23°
- Mar 48° 29°
- Apr 59° 39°
- May 70° 49°
- Jun 78° 59°
- Jul 84° 65°
- Aug 83° 63°
- Sep 76° 55°
- Oct 64° 44°
- Nov 53° 34°
- Dec 43° 27°
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 Norwich each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 21°F. The most precipitation falls in March (5.09 in), the least in July (3.63 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 38°F | 21°F | 29.5°F | 3.89 | 9.0 | 11 | <1 | 27 | 9 h 30 min |
| February | 41°F | 23°F | 31.7°F | 3.75 | 7.1 | 10 | <1 | 24 | 10 h 40 min |
| March | 48°F | 29°F | 38.6°F | 5.09 | 5.0 | 10 | <1 | 22 | 11 h 50 min |
| April | 59°F | 39°F | 49.2°F | 4.71 | 0.8 | 11 | <1 | 7 | 13 h 20 min |
| May | 70°F | 49°F | 59.4°F | 3.64 | 0.0 | 11 | 1 | <1 | 14 h 30 min |
| June | 78°F | 59°F | 68.4°F | 4.27 | 0.0 | 10 | 2 | <1 | 15 h 10 min |
| July | 84°F | 65°F | 74.4°F | 3.63 | 0.0 | 9 | 6 | <1 | 15 h |
| August | 83°F | 63°F | 72.6°F | 4.41 | 0.0 | 9 | 4 | <1 | 13 h 50 min |
| September | 76°F | 55°F | 65.2°F | 4.79 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 64°F | 44°F | 53.8°F | 4.86 | 0.0 | 10 | <1 | 4 | 11 h 10 min |
| November | 53°F | 34°F | 43.6°F | 4.17 | 0.3 | 9 | <1 | 15 | 9 h 50 min |
| December | 43°F | 27°F | 35.1°F | 4.97 | 5.6 | 11 | <1 | 25 | 9 h 10 min |
| Year (annual) | 61°F | 42°F | 51.8°F | 52.18 | 27.8 | 120 | 14 | 124 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −6°C | −1.4°C | 99 mm | 23 cm |
| February | 5°C | −5°C | −0.2°C | 95 mm | 18 cm |
| March | 9°C | −1°C | 3.7°C | 129 mm | 13 cm |
| April | 15°C | 4°C | 9.6°C | 120 mm | 2 cm |
| May | 21°C | 9°C | 15.2°C | 92 mm | 0 cm |
| June | 26°C | 15°C | 20.2°C | 108 mm | 0 cm |
| July | 29°C | 18°C | 23.6°C | 92 mm | 0 cm |
| August | 28°C | 17°C | 22.6°C | 112 mm | 0 cm |
| September | 24°C | 13°C | 18.4°C | 122 mm | 0 cm |
| October | 18°C | 6°C | 12.1°C | 123 mm | 0 cm |
| November | 12°C | 1°C | 6.4°C | 106 mm | 1 cm |
| December | 6°C | −3°C | 1.7°C | 126 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00065910; 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 Norwich?
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 USC00065910.
When is the last frost in Norwich?
In Norwich, the last spring frost (32°F) comes after April 14 in half of years and after April 30 in one year in ten; the first autumn frost comes before October 24 in half of years and before October 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
- April 141 year in 10 after April 30; 9 in 10 after April 1
- First autumn frost, half of years before
- October 241 year in 10 before October 9; 9 in 10 before November 7
NOAA puts the median frost-free season at 192 days, and the season without a hard freeze (28°F) at 216 days.
A hard freeze (28°F) comes after April 1 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Norwich in zone 6b across its 3 ZIP code areas (6b in 06360, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Norwich's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (25 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 Connecticut · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00065910; 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.
What hardiness zone is each Norwich ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Norwich's 3 ZIP code areas are all in zone 6b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Norwich?
In a normal year in Norwich, 14 days a year reach 90°F, 124 nights fall to 32°F or colder and 120 days bring measurable precipitation.
- Days at 90°F or more
- 14a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 124a normal year
- Days that stay below freezing
- 19high of 32°F or less
- Days with 0.01 inch of precipitation
- 120a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1956) is 102°F, on August 10, 2001; the lowest is −21°F, on January 21, 1994.
The wettest calendar year on that record is 2008, with 72.52 in; the snowiest season is 1995–96, with 74.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00065910; records: ACIS (NOAA Regional Climate Centers), station USC00065910. Records use complete months only; a month missing more than three days is left out.
How sunny is Norwich?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Norwich, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 1.9 |
| February | 70% | 2.7 |
| March | 69% | 3.7 |
| April | 71% | 4.9 |
| May | 70% | 5.5 |
| June | 74% | 5.9 |
| July | 79% | 6.0 |
| August | 79% | 5.3 |
| September | 78% | 4.4 |
| October | 71% | 2.9 |
| November | 72% | 2.1 |
| December | 67% | 1.5 |
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 Norwich need?
A normal year in Norwich brings 5,579 heating degree days, 4% more than the median U.S. place (5,373), and 802 cooling degree days, 12% 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 3,066 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,102 | 0 |
| February | 932 | 0 |
| March | 819 | 0 |
| April | 477 | 3 |
| May | 203 | 29 |
| June | 34 | 138 |
| July | 2 | 295 |
| August | 4 | 242 |
| September | 82 | 87 |
| October | 358 | 9 |
| November | 641 | 0 |
| December | 927 | 0 |
| Year (annual) | 5,579 | 802 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00065910. 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.
Has Norwich been warmer than normal lately?
2025 averaged 52.1°F, 0.3°F above the 1991-2020 normal of 51.8°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.5°F | +1.7°F | 47.72 | 21.9 |
| 2022 | 53.0°F | +1.2°F | 42.97 | 36.1 |
| 2023 | 54.2°F | +2.4°F | 56.97 | 0.7 |
| 2024 | 54.0°F | +2.2°F | 49.93 | 11.6 |
| 2025 | 52.1°F | +0.3°F | 45.89 | 19.3 |
Over 43 complete years from 1958 to 2025, the station's annual mean temperature rose at a fitted 2.8°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 USC00065910; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Norwich's climate compare?
Norwich is warmer than 9 of the other 12 places with their own NOAA record in Connecticut, and wetter than 11. Across the 7,247 U.S. stations with normals, its annual mean of 51.8°F is warmer than 49%.
In the Köppen classification computed from these normals, Norwich is Dfa: continental, no dry season, hot 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 Norwich share this climate record?
5 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.
- Jewett City, CT3,464 people · 7 mi NE
- Oxoboxo River, CT2,912 people · 6 mi SW
- Hope Valley, RI2,147 people · 18 mi E
- Baltic, CT1,266 people · 6 mi N
- Hopkinton, RI8,431 people · 15 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 Norwich's climate
What is the coldest month in Norwich?
January, with a normal high of 38°F and a normal low of 21°F. The warmest is July (84°F by day, 65°F at night).
Does it snow in Norwich?
Yes: 28 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (9.0 inches).
What is the rainiest month in Norwich?
March, with 5.09 in of precipitation in a normal year; the driest is July with 3.63 in.
What plant hardiness zone is Norwich in?
The USDA's 2023 map puts Norwich in zone 6b across its 3 ZIP code areas (6b in 06360, the largest). By the same method at Norwich's NOAA station, the coldest night of a typical year reaches 1°F (25 years, 1991-2020): zone 7a.
How late can frost come in Norwich?
In half of years the last 32°F night comes after April 14; in one year in ten it comes after April 30. Waiting until April 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Connecticut climateThe statewide normals and every place in the state
- Groton, CT14 miles from this station, 51.4°F a year
- Willimantic, CT16 miles from this station, 49.9°F a year
- Hampton, CT17 miles from this station, 48.6°F a year
- Westerly, RI19 miles from this station, 52.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made