Errol Airport, New Hampshire climate: Climate normals at a NOAA weather station
Errol Airport's normal year runs from 1°F January nights to 77°F July afternoons, with 44.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.2°C, January lows of −17°C, July highs of 25°C, 1,133 mm of precipitation a year.
- NOAA stationErrol Airport
- Station IDUSC00272846
- Location44.79°N 71.16°W
- Elevation1,240 ft (378 m)
On October 22, the normal high in Errol Airport is 52°F and the normal low 30°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Errol Airport.
- Jan 23° 1°
- Feb 26° -1°
- Mar 36° 11°
- Apr 49° 26°
- May 63° 39°
- Jun 72° 48°
- Jul 77° 52°
- Aug 75° 50°
- Sep 68° 43°
- Oct 55° 32°
- Nov 41° 23°
- Dec 29° 10°
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 Errol Airport each month?
July is the warmest month, with normal highs of 77°F; January the coldest, with normal lows of 1°F. The most precipitation falls in October (5.12 in), the least in February (2.62 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 23°F | 1°F | 12.3°F | 2.99 | – | <1 | 31 | 9 h 10 min |
| February | 26°F | −1°F | 12.7°F | 2.62 | – | <1 | 28 | 10 h 20 min |
| March | 36°F | 11°F | 23.4°F | 2.82 | – | <1 | 30 | 11 h 50 min |
| April | 49°F | 26°F | 37.3°F | 3.46 | – | <1 | 23 | 13 h 30 min |
| May | 63°F | 39°F | 50.7°F | 3.63 | – | <1 | 8 | 14 h 50 min |
| June | 72°F | 48°F | 60.0°F | 4.75 | – | <1 | 1 | 15 h 30 min |
| July | 77°F | 52°F | 64.5°F | 4.13 | – | 1 | <1 | 15 h 20 min |
| August | 75°F | 50°F | 62.8°F | 4.17 | – | <1 | <1 | 14 h 10 min |
| September | 68°F | 43°F | 55.6°F | 3.65 | – | <1 | 4 | 12 h 40 min |
| October | 55°F | 32°F | 43.5°F | 5.12 | – | <1 | 15 | 11 h |
| November | 41°F | 23°F | 32.1°F | 3.51 | – | <1 | 27 | 9 h 40 min |
| December | 29°F | 10°F | 19.8°F | 3.75 | – | <1 | 31 | 8 h 50 min |
| Year (annual) | 51°F | 28°F | 39.5°F | 44.60 | – | 1 | 197 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −5°C | −17°C | −10.9°C | 76 mm |
| February | −3°C | −18°C | −10.7°C | 67 mm |
| March | 2°C | −11°C | −4.8°C | 72 mm |
| April | 9°C | −3°C | 2.9°C | 88 mm |
| May | 17°C | 4°C | 10.4°C | 92 mm |
| June | 22°C | 9°C | 15.6°C | 121 mm |
| July | 25°C | 11°C | 18.1°C | 105 mm |
| August | 24°C | 10°C | 17.1°C | 106 mm |
| September | 20°C | 6°C | 13.1°C | 93 mm |
| October | 13°C | 0°C | 6.4°C | 130 mm |
| November | 5°C | −5°C | 0.1°C | 89 mm |
| December | −1°C | −12°C | −6.8°C | 95 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Colebrook (19 miles away), gets 81 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00272846; 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 Errol Airport?
Normal highs sit between 65°F and 85°F in June, July, August and September.
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 USC00272846.
When is the last frost at Errol Airport?
In Errol Airport, the last spring frost (32°F) comes after May 21 in half of years and after June 3 in one year in ten; the first autumn frost comes before September 22 in half of years and before September 9 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
- May 211 year in 10 after June 3; 9 in 10 after May 7
- First autumn frost, half of years before
- September 221 year in 10 before September 9; 9 in 10 before October 4
NOAA puts the median frost-free season at 123 days, and the season without a hard freeze (28°F) at 145 days.
A hard freeze (28°F) comes after May 8 in half of springs and before October 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Errol Airport in zone 4b in ZIP code 03579, the nearest ZIP area.
Frost dates for every NOAA station in New Hampshire · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00272846; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Errol Airport?
In a normal year in Errol Airport, 1 day a year reaches 90°F and 197 nights fall to 32°F or colder.
- Days at 90°F or more
- 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 197a normal year
- Days that stay below freezing
- 86high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00272846.
How sunny is it at Errol Airport?
Over a year 66% of the sunlight that would reach the ground under clear skies gets through the clouds at Errol Airport, 3.5 kWh per square metre a day. September is the sunniest month (73%) and December the cloudiest (54%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.4 |
| February | 62% | 2.3 |
| March | 65% | 3.5 |
| April | 64% | 4.4 |
| May | 64% | 5.1 |
| June | 67% | 5.5 |
| July | 71% | 5.6 |
| August | 73% | 5.0 |
| September | 73% | 4.0 |
| October | 62% | 2.4 |
| November | 59% | 1.6 |
| December | 54% | 1.1 |
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 Errol Airport record?
A normal year at Errol Airport brings 9,364 heating degree days, 74% more than the median U.S. place (5,373), and 123 cooling degree days, 86% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,481 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,633 | 0 |
| February | 1,464 | 0 |
| March | 1,289 | 0 |
| April | 831 | 0 |
| May | 448 | 3 |
| June | 170 | 20 |
| July | 67 | 49 |
| August | 107 | 37 |
| September | 296 | 14 |
| October | 668 | 0 |
| November | 987 | 0 |
| December | 1,403 | 0 |
| Year (annual) | 9,364 | 123 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00272846. 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 Errol Airport been warmer than normal?
2024 averaged 42.8°F, 3.3°F above the 1991-2020 normal of 39.5°F. 2 of the 2 complete years since 2023 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2023 | 42.4°F | +2.9°F | 46.74 |
| 2024 | 42.8°F | +3.3°F | 43.86 |
Source: observed years: ACIS, station USC00272846. A year counts only with all twelve months complete.
How does Errol Airport's climate compare?
Errol Airport is warmer than 0 of the 28 places with their own NOAA record in New Hampshire, and wetter than 13. Across the 7,247 U.S. stations with normals, its annual mean of 39.5°F is warmer than 5%.
In the Köppen classification computed from these normals, Errol Airport 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.
Questions about Errol Airport's climate
What is the coldest month at Errol Airport?
January, with a normal high of 23°F and a normal low of 1°F. The warmest is July (77°F by day, 52°F at night).
Does it snow at Errol Airport?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Colebrook (19 miles away), records 81 inches of snow in a normal year.
What is the rainiest month at Errol Airport?
October, with 5.12 in of precipitation in a normal year; the driest is February with 2.62 in.
What plant hardiness zone is Errol Airport in?
The USDA's 2023 map puts Errol Airport in zone 4b in ZIP code 03579, the nearest ZIP area.
How late can frost come at Errol Airport?
In half of years the last 32°F night comes after May 21; in one year in ten it comes after June 3. Waiting until June 3 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
- Middle Dam, ME12 miles from this station, 40.3°F a year
- Berlin, NH15 miles from this station, 41.4°F a year
- Colebrook, NH19 miles from this station, 39.7°F a year
- Andover 2, ME21 miles from this station, 40.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made