Rochester, Massachusetts climate: Climate normals at a NOAA weather station
Rochester's normal year runs from 20°F January nights to 82°F July afternoons, with 53.4 inches of precipitation and 31 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.3°C, January lows of −7°C, July highs of 28°C, 1,356 mm of precipitation a year.
- NOAA stationRochester
- Station IDUSC00196938
- Location41.78°N 70.92°W
- Elevation65 ft (20 m)
On October 23, the normal high in Rochester is 60°F and the normal low 41°F, and the chance of measurable rain or snow is 33%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rochester.
- Jan 38° 20°
- Feb 40° 22°
- Mar 46° 28°
- Apr 57° 37°
- May 68° 47°
- Jun 77° 56°
- Jul 82° 63°
- Aug 81° 61°
- Sep 74° 55°
- Oct 63° 44°
- Nov 52° 35°
- Dec 43° 26°
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 Rochester each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 20°F. The most precipitation falls in March (5.73 in), the least in July (3.36 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 38°F | 20°F | 29.0°F | 4.49 | 10.7 | 11 | <1 | 26 | 9 h 30 min |
| February | 40°F | 22°F | 30.6°F | 3.83 | 9.0 | 9 | <1 | 24 | 10 h 30 min |
| March | 46°F | 28°F | 37.1°F | 5.73 | 4.5 | 11 | <1 | 21 | 11 h 50 min |
| April | 57°F | 37°F | 47.1°F | 4.91 | 0.6 | 11 | <1 | 6 | 13 h 20 min |
| May | 68°F | 47°F | 57.2°F | 3.58 | 0.0 | 11 | 1 | <1 | 14 h 30 min |
| June | 77°F | 56°F | 66.3°F | 4.08 | 0.0 | 10 | 2 | <1 | 15 h 10 min |
| July | 82°F | 63°F | 72.5°F | 3.36 | 0.0 | 9 | 5 | <1 | 15 h |
| August | 81°F | 61°F | 71.1°F | 4.05 | 0.0 | 9 | 2 | <1 | 13 h 50 min |
| September | 74°F | 55°F | 64.1°F | 4.36 | 0.0 | 9 | <1 | <1 | 12 h 30 min |
| October | 63°F | 44°F | 53.1°F | 5.05 | 0.0 | 10 | <1 | 2 | 11 h 10 min |
| November | 52°F | 35°F | 43.5°F | 4.69 | 0.1 | 10 | <1 | 12 | 9 h 50 min |
| December | 43°F | 26°F | 34.7°F | 5.25 | 5.9 | 12 | <1 | 24 | 9 h 10 min |
| Year (annual) | 60°F | 41°F | 50.5°F | 53.38 | 30.8 | 123 | 10 | 115 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −7°C | −1.7°C | 114 mm | 27 cm |
| February | 4°C | −6°C | −0.8°C | 97 mm | 23 cm |
| March | 8°C | −2°C | 2.8°C | 146 mm | 11 cm |
| April | 14°C | 3°C | 8.4°C | 125 mm | 2 cm |
| May | 20°C | 8°C | 14.0°C | 91 mm | 0 cm |
| June | 25°C | 13°C | 19.1°C | 104 mm | 0 cm |
| July | 28°C | 17°C | 22.5°C | 85 mm | 0 cm |
| August | 27°C | 16°C | 21.7°C | 103 mm | 0 cm |
| September | 23°C | 13°C | 17.8°C | 111 mm | 0 cm |
| October | 17°C | 7°C | 11.7°C | 128 mm | 0 cm |
| November | 11°C | 2°C | 6.4°C | 119 mm | 0 cm |
| December | 6°C | −3°C | 1.5°C | 133 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00196938; 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 Rochester?
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 USC00196938.
When is the last frost at Rochester?
In Rochester, the last spring frost (32°F) comes after April 23 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 21 in half of years and before October 6 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 231 year in 10 after May 7; 9 in 10 after April 10
- First autumn frost, half of years before
- October 211 year in 10 before October 6; 9 in 10 before November 4
NOAA puts the median frost-free season at 180 days, and the season without a hard freeze (28°F) at 207 days.
A hard freeze (28°F) comes after April 9 in half of springs and before November 3 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rochester in zone 6b in ZIP code 02347, 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 7a: the coldest night of a typical year reaches 1°F (29 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 Massachusetts · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00196938; 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 Rochester?
In a normal year in Rochester, 10 days a year reach 90°F, 115 nights fall to 32°F or colder and 123 days bring measurable precipitation.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 115a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 123a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1900) is 102°F, on July 22, 1991; the lowest is −18°F, on January 22, 1961.
The wettest calendar year on that record is 1972, with 72.47 in; the snowiest season is 2014–15, with 72.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00196938; records: ACIS (NOAA Regional Climate Centers), station USC00196938. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Rochester?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds at Rochester, 3.9 kWh per square metre a day. August is the sunniest month (80%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.8 |
| February | 70% | 2.7 |
| March | 70% | 3.7 |
| April | 72% | 4.9 |
| May | 72% | 5.5 |
| June | 74% | 5.9 |
| July | 80% | 6.0 |
| August | 80% | 5.4 |
| September | 79% | 4.4 |
| October | 72% | 3.0 |
| November | 70% | 2.0 |
| December | 65% | 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 many heating and cooling degree days does Rochester record?
A normal year at Rochester brings 5,870 heating degree days, 9% more than the median U.S. place (5,373), and 630 cooling degree days, 31% 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 2,755 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,116 | 0 |
| February | 962 | 0 |
| March | 864 | 0 |
| April | 537 | 2 |
| May | 261 | 18 |
| June | 62 | 101 |
| July | 6 | 237 |
| August | 10 | 199 |
| September | 96 | 69 |
| October | 374 | 5 |
| November | 645 | 0 |
| December | 938 | 0 |
| Year (annual) | 5,870 | 630 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00196938. 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 Rochester been warmer than normal?
2025 averaged 50.6°F, 0.1°F above the 1991-2020 normal of 50.5°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 51.9°F | +1.4°F | 54.77 | 11.0 |
| 2022 | 51.7°F | +1.2°F | 47.69 | 20.1 |
| 2023 | 52.5°F | +2.0°F | 54.84 | 3.8 |
| 2024 | 51.8°F | +1.3°F | 55.82 | 1.3 |
| 2025 | 50.6°F | +0.1°F | 43.77 | 12.0 |
Over 68 complete years from 1952 to 2025, the station's annual mean temperature rose at a fitted 2.9°F per century (+0.16°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00196938; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rochester's climate compare?
Rochester is warmer than 24 of the 35 places with their own NOAA record in Massachusetts, and wetter than 34. Across the 7,247 U.S. stations with normals, its annual mean of 50.5°F is warmer than 43%.
In the Köppen classification computed from these normals, Rochester 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.
Questions about Rochester's climate
What is the coldest month at Rochester?
January, with a normal high of 38°F and a normal low of 20°F. The warmest is July (82°F by day, 63°F at night).
Does it snow at Rochester?
Yes: 31 inches in a normal year, falling on 10 days with 0.1 inch or more, the most in January (10.7 inches).
What is the rainiest month at Rochester?
March, with 5.73 in of precipitation in a normal year; the driest is July with 3.36 in.
What plant hardiness zone is Rochester in?
The USDA's 2023 map puts Rochester in zone 6b in ZIP code 02347, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 1°F (29 years, 1991-2020): zone 7a.
How late can frost come at Rochester?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 7. Waiting until May 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Massachusetts climateThe statewide normals and every place in the state
- Middleboro, MA7 miles from this station, 49.5°F a year
- New Bedford, MA8 miles from this station, 50.4°F a year
- Taunton, MA8 miles from this station, 50.5°F a year
- Bridgewater, MA12 miles from this station, 49.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made