Collin County climate

Collin County Weather in September

NOAA 1991-2020 normals for Mckinney Muni AP, 1.9 km from Collin County

Average highs run from 93°F on September 1 to 84°F on September 30, and lows from 70°F to 60°F. Normal precipitation for the month is 2.81 in over about 7 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Collin County, in °F, with the record for each date.406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
88°F
Average low
66°F
Precipitation
2.81 in
Record high
112°FSep 4, 2000
Record low
41°FSep 26, 2000
Chance of a freeze
0%
Days of 90°F or more
14.9
Daylight
12 h 50 min to 11 h 52 min
Cloud cover
42%
Humidity
63%
Dew point
62°F
Wind
8.3 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 193°F70°F108°F 200061°F 200422%0%
Sep 292°F70°F108°F 200063°F 200422%0%
Sep 392°F70°F109°F 200062°F 200422%0%
Sep 492°F69°F112°F 200060°F 201022%0%
Sep 591°F69°F103°F 201258°F 201022%0%
Sep 691°F69°F103°F 201256°F 201122%0%
Sep 791°F68°F106°F 202351°F 201722%0%
Sep 891°F68°F108°F 202354°F 200422%0%
Sep 990°F68°F99°F 202651°F 200423%0%
Sep 1090°F68°F100°F 201452°F 202423%0%
Sep 1190°F67°F100°F 200055°F 201723%0%
Sep 1289°F67°F101°F 201155°F 201723%0%
Sep 1389°F67°F107°F 201154°F 201423%0%
Sep 1489°F66°F100°F 202652°F 200623%0%
Sep 1589°F66°F99°F 202651°F 200823%0%
Sep 1688°F66°F99°F 202647°F 200823%0%
Sep 1788°F65°F98°F 202650°F 200823%0%
Sep 1888°F65°F98°F 200549°F 200023%0%
Sep 1987°F64°F98°F 202450°F 201223%0%
Sep 2087°F64°F100°F 202153°F 200623%0%
Sep 2187°F64°F98°F 200553°F 199923%0%
Sep 2286°F63°F100°F 200545°F 199923%0%
Sep 2386°F63°F99°F 200546°F 199923%0%
Sep 2486°F63°F98°F 202349°F 200223%0%
Sep 2586°F62°F100°F 200545°F 200023%0%
Sep 2685°F62°F99°F 200541°F 200023%0%
Sep 2785°F61°F97°F 200543°F 200023%0%
Sep 2885°F61°F99°F 200545°F 200023%0%
Sep 2984°F61°F100°F 201147°F 200623%0%
Sep 3084°F60°F96°F 199843°F 199924%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Collin County, in percent, and of at least 0.1 inch of snowfall.05101520251102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

September 1
sunrise 7:01 AM, sunset 7:51 PM
September 30
sunrise 7:20 AM, sunset 7:12 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00053914 (Mckinney Muni AP), public domain. Records: NOAA GHCN-Daily, station USW00053914, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.