Photo: Sdkb · CC BY-SA 4.0Londonderry has colder winter nights than 85% of U.S. towns
Expect July afternoons of about 83°. In July, afternoons here are cooler than in 71% of U.S. towns. Since 1901–2000, the year has warmed by 1.9°, most of all in December. Seedlings are safe outdoors from about May 3, with the first autumn frost due around October 8.
A year in Londonderry at a glance
Each month’s typical high and low, and what it brings.
What stands out about Londonderry’s climate
Compared with towns across the U.S., with Londonderry’s place in New Hampshire beside it.
What a year in Londonderry feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 156 frost-free days a year
In half of years the last 32° night comes by May 3 and the first by October 8. Frost and day counts come from NOAA’s station at Hudson 1 Sse, NH, 7 miles from the town’s center, 120 ft lower.
The 2023 USDA map puts Londonderry’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −7°. 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 67 inches of snow a winter
Snow, measured at Hudson 1 Sse, NH, is heaviest from January through February, about 17 inches a month. Precipitation (rain plus melted snow) adds up to 46 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 137 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Londonderry
92% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Hudson 1 Sse, NH.
Living with Londonderry’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
156 frost-free days in zone 6a. The last frost comes by May 3 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 8.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 66 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Londonderry from natural hazards, river flooding is the largest share (68%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Londonderry and its neighbors
Every town next door is within a degree of Londonderry in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Londonderry’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 |
|---|---|---|---|---|
| Londonderry, NH | 15° | 83° | 46" | 67" |
| Plattekill, NY | 17° | 83° | 45" | 59" |
| Greenville, PA | 18° | 83° | 43" | 62" |
| Cortland, OH | 18° | 83° | 43" | 68" |
| La Porte, IN | 17° | 83° | 40" | 65" |
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 Londonderry averaged 1.9° warmer than the 1900s. The biggest change is in December (+3.6°).
A bigger shift than in 83% 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 Londonderry compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Londonderry’s place among New Hampshire’s.
Londonderry weather by month
Highs, lows and precipitation from NOAA’s grid at Londonderry’s center; snow, wet days and snow on the ground from Hudson 1 Sse, NH. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 33° | 15° | 3.2" | 17.1" | 12 | 24 | 14° – 31° |
| February | 37° | 16° | 3.1" | 16.3" | 11 | 22 | 13° – 33° |
| March | 45° | 24° | 4.0" | 14.6" | 12 | 17 | 28° – 44° |
| April | 58° | 34° | 3.9" | 2.8" | 12 | 2 | 42° – 50° |
| May | 69° | 45° | 3.7" | 0.0" | 13 | 0 | 51° – 62° |
| June | 78° | 54° | 4.2" | 0.0" | 12 | 0 | 63° – 70° |
| July | 83° | 60° | 3.8" | 0.0" | 11 | 0 | 67° – 75° |
| August | 81° | 58° | 3.7" | 0.0" | 11 | 0 | 67° – 73° |
| September | 74° | 51° | 4.0" | 0.0" | 10 | 0 | 58° – 67° |
| October | 61° | 39° | 4.6" | 0.6" | 11 | 0 | 46° – 57° |
| November | 49° | 30° | 3.7" | 2.0" | 11 | 2 | 35° – 45° |
| December | 39° | 21° | 4.1" | 13.4" | 12 | 15 | 24° – 39° |
| Year | 59° | 37° | 46.0" | 66.8" | 137 | 81 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 13° to 33°. August is the most reliable, staying within 6°.
Where Londonderry’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 Londonderry’s center.
- Snow: Hudson 1 Sse, NH.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Hudson 1 Sse, NH, 7 miles from the town’s center, 120 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 Londonderry’s climate
What is the weather like in Londonderry?
A typical July afternoon reaches 83°, a January night drops to 15°, and about 67 inches of snow falls in a normal winter. Colder January nights than 85% of U.S. towns; cooler July afternoons than 71% of U.S. towns.
How cold does it get in Londonderry in winter?
January nights average 15°. About 162 nights a year reach 32° or below and 13 reach 0° or below. In the coldest January of the last 30 years the month averaged 14°.
How much snow does Londonderry get?
About 67 inches in a normal winter at Hudson 1 Sse, NH, heaviest from January through February, about 17 inches a month, with snow on the ground about 81 days a year.
How hot does it get in Londonderry?
July, with a typical high of 83° and a low of 60°. About 14 days a year reach 90° (Hudson 1 Sse, NH).
When is the first and last frost in Londonderry?
In half of years the last spring frost (32°) comes by May 3 and the first fall frost by October 8, about 156 frost-free days, at Hudson 1 Sse, NH.
What growing zone is Londonderry in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −7°.
What is the best time of year to visit Londonderry?
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 Londonderry getting warmer?
Yes: 1991–2020 averaged 1.9° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 83% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Londonderry.
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.