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Hillsborough County Climate

Hillsborough County, New Hampshire

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec47.4°AVG °F

Avg Annual Temp

47.4°F

Annual Precip

46.6"

Annual Snowfall

60.6"

Extreme Heat Days

10

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.3"
3.1"
3.9"
4.0"
3.6"
4.2"
3.6"
3.8"
4.0"
4.8"
3.8"
4.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

6a

Minimum winter temperature range for plant survival

Growing Degree Days

2,460

Favors cool-season crops

Last spring frost (32°F): 05/02
First fall frost (32°F): 10/08

Seasonal Overview

Comfort ZoneSpring33°57°11.5"Summer66°71°11.6"Fall39°62°12.6"Winter23°29°10.8"20°40°60°80°100°

National Comparison

Warmer than 21% of US counties
Wetter than 63% of US counties
More seasonal variation than 74% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Hillsborough County

Climate Verdict

Hillsborough County has a cool, averaging 47.4°F annually, moderately wet with 46.6 inches of annual precipitation, rare extreme heat with only 9.985714285714286 days above 90°F annually, heavy winter snowfall averaging 60.6 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 23.1°F. summers are warm — July averages 71.1°F. The 48°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

Hillsborough County closely matches the New Hampshire statewide average temperature of 45.4°F.

Climate Profile

About Hillsborough County Weather

Warmest of the North

Hillsborough County averages 47.4°F annually, which is warmer than most of the state but still cooler than the US median. It experiences a more temperate version of the humid continental climate.

One of the State's Warmest

Hillsborough is significantly warmer than the state average of 45.4°F. Its southern location allows for more heat accumulation than the northern mountain counties.

More Heat Than Northern Neighbors

Hillsborough sees 10 days of extreme heat, which is nearly double the amount experienced in northern Grafton. It also records less snowfall than its neighbors, averaging 60.6 inches.

Hotter Summers and Milder Winters

The county averages 10 days over 90°F, the second-highest in the state. Winter is relatively mild for New Hampshire, with a December-to-February average of 25.7°F.

Prioritize Cooling and Efficiency

Residents should invest in air conditioning to handle the 71.1°F July average and frequent heat days. Winter requires standard preparation for 60.6 inches of snow and January lows of 23.1°F.

Frequently Asked Questions

What is the average temperature in Hillsborough County?
The average annual temperature in Hillsborough County, NH is 47.4°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Hillsborough County get?
Hillsborough County receives an average of 46.6 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 Hillsborough County?
Yes, Hillsborough County receives an average of 60.6 inches of snowfall per year according to NOAA climate normals.
How hot does Hillsborough County get in summer?
The average summer temperature (June-August) in Hillsborough County is 68.6°F. The county experiences an average of 10 days per year above 90°F.
How cold are winters in Hillsborough County?
The average winter temperature (December-February) in Hillsborough County is 25.7°F. January, typically the coldest month, averages 23.1°F.

Track your own weather in Hillsborough County

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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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