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McMullen County Climate

JanFebMarAprMayJunJulAugSepOctNovDec71.5°AVG °F

Avg Annual Temp

71.5°F

Annual Precip

25.0"

Annual Snowfall

0.4"

Extreme Heat Days

149

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.3"
1.2"
2.0"
2.0"
3.1"
2.4"
2.6"
1.8"
3.6"
2.1"
1.4"
1.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

9b

Minimum winter temperature range for plant survival

Growing Degree Days

8,007

Excellent for heat-loving crops

Last spring frost (32°F): 02/13
First fall frost (32°F): 12/03

Seasonal Overview

Comfort ZoneSpring65°79°7.1"Summer84°86°6.9"Fall63°81°7.1"Winter54°59°3.9"20°40°60°80°100°

National Comparison

Warmer than 98% of US counties
Wetter than 21% of US counties
More seasonal variation than 8% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: McMullen County

Climate Verdict

McMullen County has a warm, averaging 71.5°F year-round, semi-arid conditions with only 25.0 inches of annual precipitation, extreme heat exposure with 148.73333333333332 days per year above 90°F, light snow averaging 0.4 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are mild, with January temperatures averaging 54.3°F. summers are hot, with July averaging 85.8°F. The 31°F seasonal variation provides noticeable but manageable change. January is typically the coldest month and August the warmest.

Outdoor & Gardening Guidance

Summer outdoor activities should be planned for early morning or evening to avoid extreme heat.

Regional Context

McMullen County is 6.0°F warmer than the Texas statewide average of 65.5°F, it is also noticeably drier, receiving 6.9 inches less precipitation than the state average, the county experiences 43.891459950657506 more extreme heat days than the state average.

Climate Profile

About McMullen County Weather

One of the nation's warmest

McMullen County averages a hot 71.5°F annually, which is far above the national median. This South Texas climate is defined by long, intense summers and very short winters.

High ranking heat in Texas

The average temperature of 71.5°F is a significant 6 degrees warmer than the Texas state average of 65.5°F. It is one of the most heat-intensive counties in the entire state.

Challenging the border heat

McMullen records 149 extreme heat days, nearly matching neighbor Maverick County's 151 days. It is slightly wetter than Maverick, receiving 25.0 inches of annual precipitation.

Perpetual summer and trace snow

The county averages 149 days over 90°F, with summer temperatures reaching 85.4°F. Winter is essentially a mild spring, with a February average of 56.2°F and only 0.4 inches of snow.

Serious cooling and sun safety

Outdoor workers and residents must plan for nearly five months of temperatures over 90°F. Industrial-grade cooling systems and sun-protective gear are essential for local life.

Frequently Asked Questions

What is the average temperature in McMullen County?
The average annual temperature in McMullen County, TX is 71.5°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does McMullen County get?
McMullen County receives an average of 25.0 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 McMullen County?
Yes, McMullen County receives an average of 0.4 inches of snowfall per year according to NOAA climate normals.
How hot does McMullen County get in summer?
The average summer temperature (June-August) in McMullen County is 85.4°F. The county experiences an average of 149 days per year above 90°F.
How cold are winters in McMullen County?
The average winter temperature (December-February) in McMullen County is 56.2°F. January, typically the coldest month, averages 54.3°F.

Track your own weather in McMullen 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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