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Johnson County Climate

Johnson County, Tennessee

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec53.4°AVG °F

Avg Annual Temp

53.4°F

Annual Precip

47.2"

Annual Snowfall

12.0"

Extreme Heat Days

3

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.7"
3.4"
4.1"
4.3"
5.2"
4.5"
5.0"
4.2"
3.3"
2.8"
2.9"
3.9"
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

3,119

Supports most vegetables & fruits

Last spring frost (32°F): 04/27
First fall frost (32°F): 10/14

Seasonal Overview

Comfort ZoneSpring44°61°13.6"Summer68°71°13.7"Fall45°65°9.0"Winter34°38°11.0"20°40°60°80°100°

National Comparison

Warmer than 45% of US counties
Wetter than 66% of US counties
More seasonal variation than 22% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Johnson County

Climate Verdict

Johnson County has a mild, with an average annual temperature of 53.4°F, moderately wet with 47.2 inches of annual precipitation, rare extreme heat with only 3.1 days above 90°F annually, light snow averaging 12.0 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 34.2°F. summers are warm — July averages 71.2°F. The 37°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Johnson County is 4.6°F cooler than the Tennessee statewide average of 58.0°F, it is also noticeably drier, receiving 8.5 inches less precipitation than the state average, the county experiences 33.35992831541217 fewer extreme heat days than the state average.

Climate Profile

About Johnson County Weather

Tennessee's high-altitude cool spot

Johnson County is one of the coolest spots in the South, with an annual average temperature of just 53.4°F. This matches the national median, offering a climate more similar to the Northeast than the Sun Belt.

The coldest county in Tennessee

Ranking far below the state average of 58.1°F, Johnson County’s 53.4°F average reflects its high-elevation terrain. It is a significant outlier in a state known for sweltering summer heat.

Distinctly cooler and snowier

Johnson County receives 12.0 inches of snow annually, nearly triple what most other Tennessee counties experience. It also records 47.2 inches of annual precipitation, which is lower than the state's 55.9-inch average.

Rare heat and real winters

The county sees only 3 days of 90°F weather per year, providing a unique escape from the Southern heat. Winters are the harshest in the state, with January temperatures averaging a chilly 34.2°F.

Invest in winter gear

Winter tires and reliable heating systems are essential for the foot of snow that falls annually. Air conditioning is less of a priority here compared to almost any other county in Tennessee.

Frequently Asked Questions

What is the average temperature in Johnson County?
The average annual temperature in Johnson County, TN is 53.4°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Johnson County get?
Johnson County receives an average of 47.2 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 Johnson County?
Yes, Johnson County receives an average of 12.0 inches of snowfall per year according to NOAA climate normals.
How hot does Johnson County get in summer?
The average summer temperature (June-August) in Johnson County is 69.9°F. The county experiences an average of 3 days per year above 90°F.
How cold are winters in Johnson County?
The average winter temperature (December-February) in Johnson County is 36.3°F. January, typically the coldest month, averages 34.2°F.

Track your own weather in Johnson 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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