Photo: John Phelan · CC BY 4.0Few U.S. towns have cooler summers than Harrisville
Midwinter brings lows of about 12°. A year here swings 66° from midwinter lows to midsummer highs. By January nights alone, it runs colder than 91% of U.S. towns. The outdoor season runs from May to September, with highs of 66–78°.
A year in Harrisville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Harrisville’s climate
Compared with towns across the U.S., with Harrisville’s place in New Hampshire beside it.
What a year in Harrisville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 152 frost-free days a year
In half of years the last 32° night comes by May 5 and the first by October 6. Day counts come from NOAA’s station at Jaffrey Silver Rch Airpark, NH, 10 miles from the town’s center, 280 ft lower; frost dates and degree days from Jaffrey Muni Airport, 10 miles away.
The 2023 USDA map puts Harrisville’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −6°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 60 inches of snow a winter
Snow, measured at Keene, NH, falls mostly in January, February and December. Precipitation (rain plus melted snow) adds up to 49 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 134 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Harrisville
94% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Jaffrey Muni Airport.
Living with Harrisville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
152 frost-free days in zone 6a. The last frost comes by May 5 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 6.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 24 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Harrisville from natural hazards, river flooding is the largest share (63%); heat waves, cold waves, winter storms and ice storms together are 11%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Harrisville and its neighbors
Peterborough the hottest July afternoons (81°, 3° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Harrisville’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Harrisville, NH | 12° | 78° | 49" | 60" |
| Delhi, NY | 13° | 79° | 46" | 71" |
| Ellsworth, ME | 11° | 79° | 48" | 75" |
| Hazleton, PA | 16° | 78° | 51" | 42" |
| Ontario, OH | 17° | 82° | 42" | 49" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Harrisville averaged 1.8° warmer than the 1900s. The biggest change is in December (+3.6°).
A bigger shift than in 82% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Harrisville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Harrisville’s place among New Hampshire’s.
Harrisville weather by month
Highs, lows and precipitation from NOAA’s grid at Harrisville’s center; snow, wet days and snow on the ground from Keene, NH. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 30° | 12° | 3.4" | 15.2" | 12 | 25 | 11° – 28° |
| February | 33° | 13° | 3.2" | 14.4" | 10 | 25 | 9° – 30° |
| March | 41° | 21° | 3.6" | 11.0" | 11 | 16 | 24° – 41° |
| April | 54° | 32° | 3.8" | 2.2" | 11 | 2 | 39° – 47° |
| May | 66° | 43° | 3.8" | 0.0" | 13 | 0 | 49° – 60° |
| June | 74° | 52° | 4.5" | 0.0" | 12 | 0 | 60° – 67° |
| July | 78° | 57° | 4.6" | 0.0" | 12 | 0 | 63° – 71° |
| August | 77° | 55° | 4.4" | 0.0" | 10 | 0 | 63° – 70° |
| September | 70° | 48° | 4.3" | 0.0" | 10 | 0 | 54° – 63° |
| October | 57° | 38° | 5.1" | 0.2" | 12 | 0 | 43° – 54° |
| November | 45° | 28° | 3.8" | 2.4" | 11 | 2 | 33° – 42° |
| December | 35° | 19° | 4.3" | 14.4" | 12 | 17 | 20° – 37° |
| Year | 55° | 35° | 48.9" | 59.8" | 134 | 87 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 9° to 30°. June is the most reliable, staying within 6°.
Where Harrisville’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Harrisville’s center.
- Snow: Keene, NH.
- Frost dates, heating and cooling: Jaffrey Muni Airport, 10 miles away.
- Freezing nights, 90° and 100° days: Jaffrey Silver Rch Airpark, NH, 10 miles from the town’s center, 280 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Harrisville’s climate
What is the weather like in Harrisville?
A typical July afternoon reaches 78°, a January night drops to 12°, and about 60 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in Harrisville in winter?
January nights average 12°. About 150 nights a year reach 32° or below and 10 reach 0° or below. In the coldest January of the last 30 years the month averaged 11°.
How much snow does Harrisville get?
About 60 inches in a normal winter at Keene, NH, most of it in January, February and December, with snow on the ground about 87 days a year.
How hot does it get in Harrisville?
July, with a typical high of 78° and a low of 57°. About 9 days a year reach 90° (Jaffrey Muni Airport).
When is the first and last frost in Harrisville?
In half of years the last spring frost (32°) comes by May 5 and the first fall frost by October 6, about 152 frost-free days, at Jaffrey Muni Airport.
What growing zone is Harrisville in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −6°.
What is the best time of year to visit Harrisville?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Harrisville getting warmer?
Yes: 1991–2020 averaged 1.8° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 82% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Harrisville.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.