Rochester, New Hampshire climate: Normal weather by month, frost dates and records
Rochester's normal year runs from 15°F January nights to 82°F July afternoons, with 41.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.7°C, January lows of −9°C, July highs of 28°C, 1,047 mm of precipitation a year.
- NOAA stationRochester Skyhaven Airport
- Station IDUSW00054791
- Location43.28°N 70.92°W
- Elevation323 ft (99 m)
- From the center3 miles
- Population33,598
On October 14, the normal high in Rochester is 61°F and the normal low 40°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 Rochester.
- Jan 33° 15°
- Feb 35° 17°
- Mar 44° 25°
- Apr 57° 35°
- May 67° 45°
- Jun 77° 54°
- Jul 82° 60°
- Aug 81° 58°
- Sep 73° 50°
- Oct 60° 39°
- Nov 48° 31°
- Dec 37° 22°
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 Rochester each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 15°F. The most precipitation falls in October (4.39 in), the least in February (2.22 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 33°F | 15°F | 24.0°F | 2.53 | 10 | <1 | 29 | 9 h 20 min |
| February | 35°F | 17°F | 26.2°F | 2.22 | 10 | <1 | 27 | 10 h 30 min |
| March | 44°F | 25°F | 34.1°F | 3.72 | 11 | <1 | 25 | 11 h 50 min |
| April | 57°F | 35°F | 45.7°F | 3.67 | 12 | <1 | 12 | 13 h 20 min |
| May | 67°F | 45°F | 56.1°F | 3.52 | 13 | 1 | 1 | 14 h 40 min |
| June | 77°F | 54°F | 65.6°F | 3.86 | 14 | 2 | <1 | 15 h 20 min |
| July | 82°F | 60°F | 70.8°F | 3.52 | 13 | 5 | <1 | 15 h 10 min |
| August | 81°F | 58°F | 69.3°F | 3.17 | 12 | 3 | <1 | 14 h |
| September | 73°F | 50°F | 61.5°F | 3.43 | 11 | 1 | <1 | 12 h 30 min |
| October | 60°F | 39°F | 49.8°F | 4.39 | 12 | <1 | 6 | 11 h 10 min |
| November | 48°F | 31°F | 39.4°F | 3.89 | 10 | <1 | 18 | 9 h 40 min |
| December | 37°F | 22°F | 29.6°F | 3.30 | 11 | <1 | 27 | 9 h |
| Year (annual) | 58°F | 38°F | 47.7°F | 41.22 | 139 | 11 | 145 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 0°C | −9°C | −4.4°C | 64 mm |
| February | 2°C | −8°C | −3.2°C | 56 mm |
| March | 6°C | −4°C | 1.2°C | 94 mm |
| April | 14°C | 2°C | 7.6°C | 93 mm |
| May | 20°C | 7°C | 13.4°C | 89 mm |
| June | 25°C | 12°C | 18.7°C | 98 mm |
| July | 28°C | 15°C | 21.6°C | 89 mm |
| August | 27°C | 14°C | 20.7°C | 81 mm |
| September | 23°C | 10°C | 16.4°C | 87 mm |
| October | 16°C | 4°C | 9.9°C | 112 mm |
| November | 9°C | −1°C | 4.1°C | 99 mm |
| December | 3°C | −6°C | −1.3°C | 84 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Durham station (9 miles away), gets 39 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00054791; 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 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 (11).
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 USW00054791.
When is the last frost in Rochester?
In Rochester, the last spring frost (32°F) comes after April 30 in half of years and after May 13 in one year in ten; the first autumn frost comes before October 9 in half of years and before September 27 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 301 year in 10 after May 13; 9 in 10 after April 18
- First autumn frost, half of years before
- October 91 year in 10 before September 27; 9 in 10 before October 25
NOAA puts the median frost-free season at 161 days, and the season without a hard freeze (28°F) at 188 days.
A hard freeze (28°F) comes after April 17 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rochester in zone 6a across its 3 ZIP code areas (6a in 03867, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Rochester's NOAA station is in zone 6a: the coldest night of a typical year reaches −7°F (19 complete years).
Frost dates for every NOAA station in New Hampshire · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00054791; 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 Rochester ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Rochester's 3 ZIP code areas are all in zone 6a. 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 Rochester?
In a normal year in Rochester, 11 days a year reach 90°F, 145 nights fall to 32°F or colder and 139 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 145a normal year
- Days that stay below freezing
- 42high of 32°F or less
- Days with 0.01 inch of precipitation
- 139a normal year
The highest temperature in this station's record (since 2000) is 100°F, on June 24, 2025; the lowest is −15°F, on January 16, 2009.
The wettest calendar year on that record is 2008, with 58.53 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00054791; records: ACIS (NOAA Regional Climate Centers), station USW00054791. Records use complete months only; a month missing more than three days is left out.
How sunny is Rochester?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Rochester, 3.8 kWh per square metre a day. August is the sunniest month (79%) and December the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.7 |
| February | 69% | 2.5 |
| March | 69% | 3.6 |
| April | 70% | 4.7 |
| May | 69% | 5.3 |
| June | 70% | 5.6 |
| July | 77% | 5.9 |
| August | 79% | 5.3 |
| September | 78% | 4.3 |
| October | 70% | 2.8 |
| November | 68% | 1.8 |
| December | 64% | 1.4 |
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 Rochester need?
A normal year in Rochester brings 6,790 heating degree days, 26% more than the median U.S. place (5,373), and 506 cooling degree days, 44% 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 2,438 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,271 | 0 |
| February | 1,086 | 0 |
| March | 958 | 0 |
| April | 582 | 3 |
| May | 294 | 18 |
| June | 74 | 92 |
| July | 12 | 190 |
| August | 21 | 152 |
| September | 155 | 48 |
| October | 472 | 3 |
| November | 770 | 0 |
| December | 1,096 | 0 |
| Year (annual) | 6,790 | 506 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00054791. 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 Rochester been warmer than normal lately?
2024 averaged 52.6°F, 4.9°F above the 1991-2020 normal of 47.7°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 49.9°F | +2.2°F | 43.58 |
| 2022 | 50.1°F | +2.4°F | 42.27 |
| 2023 | 51.6°F | +3.9°F | 55.32 |
| 2024 | 52.6°F | +4.9°F | 37.42 |
Source: observed years: ACIS, station USW00054791. A year counts only with all twelve months complete.
How does Rochester's climate compare?
Rochester is warmer than 22 of the other 27 places with their own NOAA record in New Hampshire, and wetter than 7. Across the 7,247 U.S. stations with normals, its annual mean of 47.7°F is warmer than 31%.
In the Köppen classification computed from these normals, Rochester 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 Rochester share this climate record?
4 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.
- Somersworth, NH12,218 people · 2 mi SE
- South Berwick, ME7,824 people · 7 mi SE
- Berwick, ME8,332 people · 3 mi E
- North Berwick, ME5,257 people · 10 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 Rochester's climate
What is the coldest month in Rochester?
January, with a normal high of 33°F and a normal low of 15°F. The warmest is July (82°F by day, 60°F at night).
Does it snow in Rochester?
Yes. NOAA publishes no 1991-2020 snowfall normal for Rochester's NOAA station; the nearest record that keeps one, Durham station (9 miles away), records 39 inches of snow in a normal year.
What is the rainiest month in Rochester?
October, with 4.39 in of precipitation in a normal year; the driest is February with 2.22 in.
What plant hardiness zone is Rochester in?
The USDA's 2023 map puts Rochester in zone 6a across its 3 ZIP code areas (6a in 03867, the largest). By the same method at Rochester's NOAA station, the coldest night of a typical year reaches −7°F (19 years, 1991-2020): zone 6a.
How late can frost come in Rochester?
In half of years the last 32°F night comes after April 30; in one year in ten it comes after May 13. Waiting until May 13 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
- Durham, NH7 miles from this station, 47.1°F a year
- Sanford, ME14 miles from this station, 45.5°F a year
- Cape Neddick, ME15 miles from this station, 46.9°F a year
- Greenland, NH19 miles from this station, 47.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made