weatherbycounty

Johnson County Climate

JanFebMarAprMayJunJulAugSepOctNovDec45.1°AVG °F

Avg Annual Temp

45.1°F

Annual Precip

13.7"

Annual Snowfall

39.7"

Extreme Heat Days

27

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.3"
0.4"
0.7"
1.6"
3.0"
2.0"
1.5"
0.8"
1.3"
1.2"
0.5"
0.3"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5a

Minimum winter temperature range for plant survival

Growing Degree Days

2,092

Favors cool-season crops

Last spring frost (32°F): 05/19
First fall frost (32°F): 09/25

Seasonal Overview

Comfort ZoneSpring35°51°5.3"Summer62°70°4.3"Fall34°59°2.9"Winter25°26°1.1"20°40°60°80°100°

National Comparison

Warmer than 13% of US counties
Wetter than 5% of US counties
More seasonal variation than 62% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Johnson County

Climate Verdict

Johnson County has a cool, averaging 45.1°F annually, arid conditions receiving just 13.7 inches of precipitation annually, occasional hot days — 26.9 per year above 90°F, moderate snowfall of 39.7 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 24.9°F. summers are warm — July averages 70.2°F. The 45°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 closely matches the Wyoming statewide average temperature of 43.8°F.

Climate Profile

About Johnson County Weather

High Altitude and Dry Air

Johnson County maintains an average annual temperature of 45.1°F, reflecting its position in the cool, dry interior of the Mountain West. Precipitation is sparse, with only 13.7 inches of moisture annually.

Classic Wyoming Weather Patterns

At 45.1°F, the county is roughly 1.3 degrees warmer than the statewide average of 43.8°F. It is one of several central-northern counties that experience slightly more temperate conditions than the state's highest peaks.

Temperatures Close to Local Peers

Johnson County is slightly cooler than neighboring Natrona County to the south, which averages 45.7°F. It mirrors the general climate of the Big Horn Basin but with slightly more moisture than Hot Springs County.

Predictable Heat and Moderate Snow

July brings an average of 70.2°F and 27 days of extreme heat over 90°F. Winter delivers a manageable 39.7 inches of snowfall, which is relatively low for Wyoming's mountainous regions.

Planning for Arid Conditions

With only 13.7 inches of annual precipitation, water conservation and xeriscaping are practical choices for residents. Winter gear should focus on wind protection as January temperatures average a brisk 24.9°F.

Frequently Asked Questions

What is the average temperature in Johnson County?
The average annual temperature in Johnson County, WY is 45.1°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Johnson County get?
Johnson County receives an average of 13.7 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 39.7 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 66.7°F. The county experiences an average of 27 days per year above 90°F.
How cold are winters in Johnson County?
The average winter temperature (December-February) in Johnson County is 25.3°F. January, typically the coldest month, averages 24.9°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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