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Jefferson County Climate

Jefferson County, Tennessee

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec55.9°AVG °F

Avg Annual Temp

55.9°F

Annual Precip

48.5"

Annual Snowfall

3.0"

Extreme Heat Days

24

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
4.1"
4.5"
4.6"
4.6"
4.1"
3.8"
5.0"
3.8"
3.3"
2.7"
3.4"
4.5"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

7b

Minimum winter temperature range for plant survival

Growing Degree Days

3,763

Supports most vegetables & fruits

Last spring frost (32°F): 04/24
First fall frost (32°F): 10/17

Seasonal Overview

Comfort ZoneSpring46°64°13.4"Summer72°75°12.6"Fall46°68°9.4"Winter36°39°13.1"20°40°60°80°100°

National Comparison

Warmer than 56% of US counties
Wetter than 71% of US counties
More seasonal variation than 31% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Jefferson County

Climate Verdict

Jefferson County has a mild, with an average annual temperature of 55.9°F, moderately wet with 48.5 inches of annual precipitation, occasional hot days — 24.2 per year above 90°F, light snow averaging 3.0 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 35.9°F. summers are warm — July averages 75.0°F. The 39°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.

Regional Context

Jefferson County closely matches the Tennessee statewide average temperature of 58.0°F, it is also noticeably drier, receiving 7.1 inches less precipitation than the state average.

Climate Profile

About Jefferson County Weather

A mild East Tennessee climate

Jefferson County features an annual average temperature of 55.9°F, which is very close to the national climate median. This makes the region cooler and more temperate than much of the Deep South.

Among Tennessee's cooler counties

With an average of 55.9°F, Jefferson County is significantly cooler than the Tennessee state average of 58.1°F. Its location in the Appalachian Valley provides relief from the more intense heat found in West Tennessee.

Drier than the state average

The county receives 48.5 inches of rain annually, which is nearly 7 inches less than the state average. This drier profile distinguishes it from the wetter counties located further west on the Highland Rim.

Temperate summers and mild winters

Extreme heat is less common here, with only 24 days reaching 90°F each year. Winter brings a modest 3.0 inches of snowfall and an average December-to-February temperature of 37.9°F.

Ideal for outdoor recreation

Lower humidity and fewer extreme heat days make this county excellent for outdoor activities during the 73.7°F average summer. Homeowners should plan for occasional winter freezes, though heavy snow accumulation is rare.

Frequently Asked Questions

What is the average temperature in Jefferson County?
The average annual temperature in Jefferson County, TN is 55.9°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Jefferson County get?
Jefferson County receives an average of 48.5 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 Jefferson County?
Yes, Jefferson County receives an average of 3.0 inches of snowfall per year according to NOAA climate normals.
How hot does Jefferson County get in summer?
The average summer temperature (June-August) in Jefferson County is 73.7°F. The county experiences an average of 24 days per year above 90°F.
How cold are winters in Jefferson County?
The average winter temperature (December-February) in Jefferson County is 37.9°F. January, typically the coldest month, averages 35.9°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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