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Williamson County Climate

Williamson County, Tennessee

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec59.0°AVG °F

Avg Annual Temp

59.0°F

Annual Precip

55.3"

Annual Snowfall

2.6"

Extreme Heat Days

48

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
4.6"
4.9"
5.3"
5.2"
5.5"
4.5"
4.7"
3.6"
4.0"
3.7"
4.0"
5.3"
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

4,630

Excellent for heat-loving crops

Last spring frost (32°F): 04/07
First fall frost (32°F): 10/31

Seasonal Overview

Comfort ZoneSpring49°67°16.0"Summer75°79°12.8"Fall49°72°11.7"Winter38°41°14.8"20°40°60°80°100°

National Comparison

Warmer than 68% of US counties
Wetter than 88% of US counties
More seasonal variation than 41% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Williamson County

Climate Verdict

Williamson County has a mild, with an average annual temperature of 59.0°F, very wet conditions receiving 55.3 inches of precipitation annually, occasional hot days — 48.300000000000004 per year above 90°F, light snow averaging 2.6 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 37.8°F. summers are warm — July averages 78.9°F. The 41°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

Williamson County closely matches the Tennessee statewide average temperature of 58.0°F.

Climate Profile

About Williamson County Weather

Warm and Growing Seasons

Williamson County’s 59.0°F annual average is much higher than the national median. This warmth supports a long growing season and a characteristic Southern climate.

Among Tennessee's Warmer Counties

At 59.0°F, Williamson is nearly a full degree warmer than the state average of 58.1°F. It ranks as one of the warmer urban-adjacent counties in the state.

Warmer Than Surrounding Rural Areas

Williamson is warmer than Trousdale (57.9°F) and White County (58.0°F). Its climate is more consistent with the lower-elevation basins of Middle Tennessee.

Significant Summer Heat Peaks

The county sees 48 days of temperatures reaching 90°F or higher, with a July average of 78.9°F. Winters are mild with only 2.6 inches of annual snowfall.

Focus on Summer Electricity Costs

The 48 days of extreme heat mean air conditioning units will work overtime for nearly two months of the year. Minimal snowfall of 2.6 inches means winter road prep is only occasionally necessary.

Frequently Asked Questions

What is the average temperature in Williamson County?
The average annual temperature in Williamson County, TN is 59.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Williamson County get?
Williamson County receives an average of 55.3 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 Williamson County?
Yes, Williamson County receives an average of 2.6 inches of snowfall per year according to NOAA climate normals.
How hot does Williamson County get in summer?
The average summer temperature (June-August) in Williamson County is 77.4°F. The county experiences an average of 48 days per year above 90°F.
How cold are winters in Williamson County?
The average winter temperature (December-February) in Williamson County is 40.0°F. January, typically the coldest month, averages 37.8°F.

Track your own weather in Williamson 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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