Westerly, Rhode Island climate: Normal weather by month, frost dates and records
Westerly's normal year runs from 25°F January nights to 82°F July afternoons, with 42.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.4°C, January lows of −4°C, July highs of 28°C, 1,087 mm of precipitation a year.
- NOAA stationWesterly State Airport
- Station IDUSW00014794
- Location41.35°N 71.80°W
- Elevation81 ft (25 m)
- From the center2 miles
- Population (town)23,288
- Census place18,528
On October 14, the normal high in Westerly is 65°F and the normal low 47°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Westerly.
- Jan 40° 25°
- Feb 41° 26°
- Mar 47° 32°
- Apr 57° 41°
- May 67° 50°
- Jun 75° 59°
- Jul 82° 66°
- Aug 81° 64°
- Sep 74° 57°
- Oct 64° 47°
- Nov 54° 38°
- Dec 45° 30°
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 Westerly each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 25°F. The most precipitation falls in October (4.29 in), the least in February (2.75 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 25°F | 32.0°F | 3.34 | 11 | <1 | 25 | 9 h 30 min |
| February | 41°F | 26°F | 33.4°F | 2.75 | 9 | <1 | 23 | 10 h 40 min |
| March | 47°F | 32°F | 39.6°F | 4.17 | 10 | <1 | 19 | 11 h 50 min |
| April | 57°F | 41°F | 48.9°F | 3.90 | 11 | <1 | 6 | 13 h 20 min |
| May | 67°F | 50°F | 58.3°F | 3.32 | 12 | <1 | <1 | 14 h 30 min |
| June | 75°F | 59°F | 67.2°F | 3.55 | 11 | <1 | <1 | 15 h 10 min |
| July | 82°F | 66°F | 73.8°F | 2.91 | 9 | 2 | <1 | 14 h 50 min |
| August | 81°F | 64°F | 72.4°F | 3.49 | 9 | 1 | <1 | 13 h 50 min |
| September | 74°F | 57°F | 65.7°F | 3.81 | 10 | <1 | <1 | 12 h 30 min |
| October | 64°F | 47°F | 55.2°F | 4.29 | 11 | <1 | 3 | 11 h 10 min |
| November | 54°F | 38°F | 45.9°F | 3.50 | 10 | <1 | 11 | 9 h 50 min |
| December | 45°F | 30°F | 37.6°F | 3.77 | 11 | <1 | 22 | 9 h 10 min |
| Year (annual) | 61°F | 45°F | 52.5°F | 42.80 | 123 | 3 | 109 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −4°C | 0.0°C | 85 mm |
| February | 5°C | −4°C | 0.8°C | 70 mm |
| March | 8°C | 0°C | 4.2°C | 106 mm |
| April | 14°C | 5°C | 9.4°C | 99 mm |
| May | 19°C | 10°C | 14.6°C | 84 mm |
| June | 24°C | 15°C | 19.6°C | 90 mm |
| July | 28°C | 19°C | 23.2°C | 74 mm |
| August | 27°C | 18°C | 22.4°C | 89 mm |
| September | 24°C | 14°C | 18.7°C | 97 mm |
| October | 18°C | 8°C | 12.9°C | 109 mm |
| November | 12°C | 3°C | 7.7°C | 89 mm |
| December | 7°C | −1°C | 3.1°C | 96 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Groton station (12 miles away), gets 25 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014794; 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 Westerly?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, July 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 USW00014794.
When is the last frost in Westerly?
In Westerly, the last spring frost (32°F) comes after April 11 in half of years and after April 26 in one year in ten; the first autumn frost comes before October 31 in half of years and before October 16 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 111 year in 10 after April 26; 9 in 10 after March 31
- First autumn frost, half of years before
- October 311 year in 10 before October 16; 9 in 10 before November 12
NOAA puts the median frost-free season at 201 days, and the season without a hard freeze (28°F) at 227 days.
A hard freeze (28°F) comes after March 29 in half of springs and before November 11 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Westerly in zone 7a in ZIP code 02891. By the map's own method, the average of each year's coldest night over 1991-2020, Westerly's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (20 complete years).
Frost dates for every NOAA station in Rhode Island · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00014794; 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 in Westerly?
In a normal year in Westerly, 3 days a year reach 90°F, 109 nights fall to 32°F or colder and 123 days bring measurable precipitation.
- Days at 90°F or more
- 3a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 109a normal year
- Days that stay below freezing
- 19high of 32°F or less
- Days with 0.01 inch of precipitation
- 123a normal year
The highest temperature in this station's record (since 1999) is 100°F, on July 7, 2010; the lowest is −10°F, on February 21, 2015.
The wettest calendar year on that record is 2019, with 59.14 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014794; records: ACIS (NOAA Regional Climate Centers), station USW00014794. Records use complete months only; a month missing more than three days is left out.
How sunny is Westerly?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Westerly, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 1.9 |
| February | 71% | 2.7 |
| March | 71% | 3.8 |
| April | 72% | 5.0 |
| May | 72% | 5.6 |
| June | 76% | 6.1 |
| July | 81% | 6.2 |
| August | 81% | 5.5 |
| September | 79% | 4.5 |
| October | 72% | 3.0 |
| November | 71% | 2.1 |
| December | 67% | 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 Westerly need?
A normal year in Westerly brings 5,249 heating degree days, 2% fewer than the median U.S. place (5,373), and 727 cooling degree days, 20% 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 3,008 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,023 | 0 |
| February | 883 | 0 |
| March | 787 | 0 |
| April | 484 | 1 |
| May | 221 | 14 |
| June | 42 | 108 |
| July | 1 | 273 |
| August | 4 | 233 |
| September | 65 | 88 |
| October | 315 | 11 |
| November | 573 | 0 |
| December | 849 | 0 |
| Year (annual) | 5,249 | 727 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014794. 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 Westerly been warmer than normal lately?
2025 averaged 50.8°F, 1.7°F below the 1991-2020 normal of 52.5°F. 1 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 51.0°F | −1.5°F | 35.36 |
| 2022 | 52.1°F | −0.4°F | 35.23 |
| 2023 | 53.1°F | +0.6°F | 42.51 |
| 2024 | 52.5°F | at normal | 50.87 |
| 2025 | 50.8°F | −1.7°F | – |
Source: observed years: ACIS, station USW00014794. A year counts only with all twelve months complete.
How does Westerly's climate compare?
Westerly is warmer than 4 of the other 5 places with their own NOAA record in Rhode Island, and wetter than 1. Across the 7,247 U.S. stations with normals, its annual mean of 52.5°F is warmer than 52%.
In the Köppen classification computed from these normals, Westerly is Cfa: temperate, 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 Westerly share this climate record?
13 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.
- Pawcatuck, CT5,475 people · 3 mi NW
- Mystic, CT4,441 people · 8 mi W
- Old Mystic, CT3,189 people · 10 mi W
- Ashaway, RI1,682 people · 5 mi N
- Noank, CT1,617 people · 10 mi W
- Bradford, RI1,437 people · 3 mi NE
- Poquonock Bridge, CT1,108 people · 11 mi W
- Gales Ferry, CT1,027 people · 16 mi W
- Stonington, CT1,012 people · 5 mi W
- Quonochontaug, RI577 people · 5 mi E
- Groton Long Point, CT520 people · 11 mi W
- Weekapaug, RI471 people · 2 mi SE
- Mashantucket, CT93 people · 12 mi NW
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 Westerly's climate
What is the coldest month in Westerly?
January, with a normal high of 40°F and a normal low of 25°F. The warmest is July (82°F by day, 66°F at night).
Does it snow in Westerly?
Yes. NOAA publishes no 1991-2020 snowfall normal for Westerly's NOAA station; the nearest record that keeps one, Groton station (12 miles away), records 25 inches of snow in a normal year.
What is the rainiest month in Westerly?
October, with 4.29 in of precipitation in a normal year; the driest is February with 2.75 in.
What plant hardiness zone is Westerly in?
The USDA's 2023 map puts Westerly in zone 7a in ZIP code 02891. By the same method at Westerly's NOAA station, the coldest night of a typical year reaches 1°F (20 years, 1991-2020): zone 7a.
How late can frost come in Westerly?
In half of years the last 32°F night comes after April 11; in one year in ten it comes after April 26. Waiting until April 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Westerly in OctoberThis month day by day, its records and recent years
- Rhode Island climateThe statewide normals and every place in the state
- Groton, CT13 miles from this station, 51.4°F a year
- Kingston, RI16 miles from this station, 49.2°F a year
- Norwich, CT19 miles from this station, 51.8°F a year
- Montauk, NY20 miles from this station, 53.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made