weatherbycounty

Collin County Climate

JanFebMarAprMayJunJulAugSepOctNovDec65.0°AVG °F

Avg Annual Temp

65.0°F

Annual Precip

40.5"

Annual Snowfall

1.4"

Extreme Heat Days

93

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
2.7"
2.9"
3.6"
3.7"
5.0"
3.9"
2.2"
2.3"
3.0"
4.8"
3.2"
3.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

8b

Minimum winter temperature range for plant survival

Growing Degree Days

6,113

Excellent for heat-loving crops

Last spring frost (32°F): 03/17
First fall frost (32°F): 11/19

Seasonal Overview

Comfort ZoneSpring57°72°12.3"Summer80°84°8.3"Fall55°77°11.0"Winter45°49°9.0"20°40°60°80°100°

National Comparison

Warmer than 87% of US counties
Wetter than 47% of US counties
More seasonal variation than 30% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Collin County

Climate Verdict

Collin County has a warm, averaging 65.0°F year-round, moderately wet with 40.5 inches of annual precipitation, significant summer heat with 93.35000000000001 days annually above 90°F, light snow averaging 1.4 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are mild, with January temperatures averaging 44.9°F. summers are hot, with July averaging 83.8°F. The 39°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Collin County closely matches the Texas statewide average temperature of 65.5°F, it is also noticeably wetter, receiving 8.7 inches more precipitation than the state average.

Climate Profile

About Collin County Weather

Warm climate with high humidity

Collin County’s average temperature of 65.0°F is well above the national median, supported by a generous 40.5 inches of annual rain. This creates a humid subtropical environment with more precipitation than many neighboring western regions.

Cooler and wetter than the state

While the 65.0°F annual temperature is just below the Texas average, Collin County is significantly wetter than the state median. It receives over eight inches more rainfall than the typical Texas county.

Dampest in the North Texas corridor

Compared to Cooke County to the northwest, Collin is nearly two degrees warmer on average. It maintains a similar precipitation level to its northern neighbors, distinguishing itself from the drier counties further west.

Steamy summers and brisk winters

July averages a high of 83.8°F, contributing to 93 days of extreme heat over 90°F each year. Winter snowfall is negligible at 1.4 inches, though January temperatures average a cool 44.9°F.

Manage moisture and peak heat

With over 40 inches of rain, proper drainage and gutter maintenance are essential for local homeowners. Residents should also prepare for roughly three months of days exceeding 90°F with robust air conditioning.

Frequently Asked Questions

What is the average temperature in Collin County?
The average annual temperature in Collin County, TX is 65.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Collin County get?
Collin County receives an average of 40.5 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 Collin County?
Yes, Collin County receives an average of 1.4 inches of snowfall per year according to NOAA climate normals.
How hot does Collin County get in summer?
The average summer temperature (June-August) in Collin County is 82.6°F. The county experiences an average of 93 days per year above 90°F.
How cold are winters in Collin County?
The average winter temperature (December-February) in Collin County is 46.8°F. January, typically the coldest month, averages 44.9°F.

Track your own weather in Collin 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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