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Grundy County Climate

Grundy County, Tennessee

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec54.9°AVG °F

Avg Annual Temp

54.9°F

Annual Precip

63.2"

Annual Snowfall

Extreme Heat Days

8

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet
5.8"
5.5"
6.1"
6.2"
5.1"
5.3"
6.1"
4.3"
4.2"
3.5"
4.8"
6.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

7a

Minimum winter temperature range for plant survival

Growing Degree Days

3,486

Supports most vegetables & fruits

Last spring frost (32°F): 04/21
First fall frost (32°F): 10/20

Seasonal Overview

Comfort ZoneSpring46°63°17.4"Summer70°73°15.6"Fall46°67°12.5"Winter35°38°17.7"20°40°60°80°100°

National Comparison

Warmer than 51% of US counties
Wetter than 98% of US counties
More seasonal variation than 25% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Grundy County

Climate Verdict

Grundy County has a mild, with an average annual temperature of 54.9°F, very wet conditions receiving 63.2 inches of precipitation annually, rare extreme heat with only 7.5 days above 90°F annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 35.4°F. summers are warm — July averages 73.2°F. The 38°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Growing season and gardening data is currently limited for Grundy County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Grundy County is 3.1°F cooler than the Tennessee statewide average of 58.0°F, it is also noticeably wetter, receiving 7.5 inches more precipitation than the state average, the county experiences 28.95992831541217 fewer extreme heat days than the state average.

Climate Profile

About Grundy County Weather

Cool Plateau Weather Patterns

Grundy County's 54.9°F average temperature is very close to the national median. It is characterized by heavy annual precipitation, totaling a significant 63.2 inches.

One of Tennessee's Coolest Counties

Grundy ranks well below the Tennessee state average of 58.1°F. Its position on the plateau keeps it substantially cooler than the low-lying river valleys nearby.

The Wettest in the Region

Grundy's 63.2 inches of rain surpasses neighbors like Franklin and Hamilton. It is also nearly 4 degrees cooler on average than Hamilton County.

Very Few Extreme Heat Days

The county only sees 8 days of extreme heat above 90°F, offering some of the most comfortable summers in the state. While specific snowfall data is limited, the 35.4°F January average suggests cold, crisp winters.

Gear Up for Heavy Rain

Reliable waterproof gear and high-capacity drainage systems are essential for the 63-inch annual rainfall. You can save on cooling costs here, as 90-degree days are relatively rare.

Frequently Asked Questions

What is the average temperature in Grundy County?
The average annual temperature in Grundy County, TN is 54.9°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Grundy County get?
Grundy County receives an average of 63.2 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
How hot does Grundy County get in summer?
The average summer temperature (June-August) in Grundy County is 71.7°F. The county experiences an average of 8 days per year above 90°F.
How cold are winters in Grundy County?
The average winter temperature (December-February) in Grundy County is 37.4°F. January, typically the coldest month, averages 35.4°F.

Track your own weather in Grundy 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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