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Grafton County Climate

Grafton County, New Hampshire

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec44.2°AVG °F

Avg Annual Temp

44.2°F

Annual Precip

42.8"

Annual Snowfall

74.2"

Extreme Heat Days

6

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
2.8"
2.4"
3.0"
3.3"
3.6"
4.1"
4.4"
4.0"
3.6"
4.5"
3.4"
3.6"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5a

Minimum winter temperature range for plant survival

Growing Degree Days

2,054

Favors cool-season crops

Last spring frost (32°F): 05/15
First fall frost (32°F): 09/28

Seasonal Overview

Comfort ZoneSpring30°55°10.0"Summer63°68°12.5"Fall36°59°11.5"Winter18°25°8.8"20°40°60°80°100°

National Comparison

Warmer than 10% of US counties
Wetter than 52% of US counties
More seasonal variation than 81% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Grafton County

Climate Verdict

Grafton County has a cool, averaging 44.2°F annually, moderately wet with 42.8 inches of annual precipitation, rare extreme heat with only 6.057142857142857 days above 90°F annually, heavy winter snowfall averaging 74.2 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 18.3°F. summers are pleasantly cool with July averaging 68.3°F. The 50°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Grafton County closely matches the New Hampshire statewide average temperature of 45.4°F, it is somewhat drier than average for New Hampshire.

Climate Profile

About Grafton County Weather

Cool Temps and Low Moisture

Grafton County averages 44.2°F annually, which is well below the national median. It experiences a classic northern climate with sharp winters and moderate humidity.

Cooler Than the State Median

The county sits about 1.2 degrees below the New Hampshire state average of 45.4°F. This cooler profile is driven by the mountainous terrain found throughout the region.

The Drier Side of the State

Grafton is notably drier than its neighbors, receiving only 42.8 inches of precipitation compared to the 46.4-inch state average. It shares a similar temperature profile with Carroll County.

Vigorous Winters and Gentle Summers

Snowfall is a major factor here, averaging 74.2 inches per year. While winter averages are a cold 21.3°F, summers are pleasant with only 6 days of extreme heat.

Plan for Cold and Snow

With January averages of 18.3°F, reliable thermal protection for homes and vehicles is critical. Summer cooling is less urgent, as the average temperature from June to August is a mild 66.0°F.

Frequently Asked Questions

What is the average temperature in Grafton County?
The average annual temperature in Grafton County, NH is 44.2°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Grafton County get?
Grafton County receives an average of 42.8 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Grafton County?
Yes, Grafton County receives an average of 74.2 inches of snowfall per year according to NOAA climate normals.
How hot does Grafton County get in summer?
The average summer temperature (June-August) in Grafton County is 66.0°F. The county experiences an average of 6 days per year above 90°F.
How cold are winters in Grafton County?
The average winter temperature (December-February) in Grafton County is 21.3°F. January, typically the coldest month, averages 18.3°F.

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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