McKinney, TX weather in September
McKinney is hot, often humid and mostly dry in September: highs average 88°F and nights drop to about 66°F. There are about 6 days with rain.
- Normal high
- 88°F
- Normal low
- 66°F
- Wet days
- 6
- 2.9 in total
- Muggy days
- 14
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 93°F | 84°F |
| Normal low | 70°F | 60°F |
| Chance of a wet day | 20% | 19% |
| Sunrise / sunset | 7:00 am / 7:52 pm | 7:20 am / 7:12 pm |
| Daylight | 12.8 h | 11.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Central Time).
A typical September day
- 6 am71°Fdew point 64°F
- 9 am77°Fdew point 65°F
- Noon85°Fdew point 63°F
- 3 pm87°Fdew point 61°F
- 6 pm85°Fdew point 61°F
- 9 pm78°Fdew point 62°F
NOAA hourly normals (local standard time) from Dallas Ft Worth Airport (31 mi away); average wind 9 mph; clear or few clouds in 39% of daytime hours, mostly cloudy or overcast in 37%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F2 of 30
- Hot dayshigh 90°F or more15 of 30
- Muggy daysdaily mean dew point 65°F or more14 of 30
- Wet daysat least 0.01 in of rain or melted snow6 of 30
- Notable rainat least 0.10 in4 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 2.9 in; a dry September brings about 1.0 in and a wet one about 3.7 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202019: average high 94°F
- Coolest September2001: average high 83°F
- Wettest September2018: 13.2 in
- Driest September2019: no measurable precipitation
- Highest reading112°F (September 4, 2000)
- Lowest reading41°F (September 26, 2000)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 96°F | 88°F | 78°F |
| Normal low | 73°F | 66°F | 54°F |
| Wet days | 6 | 6 | 7 |
| Comfortable days | 0 | 2 | 12 |
| Daylight | 13.3 h | 12.4 h | 11.3 h |
Highs change by -8°F from August and -10°F into October.
Nearby alternatives in September
- Cooler: Fayetteville, AR242 mi · high 82°F · 9 wet days
How McKinney ranks in September
- Normal high96th warmest of 378 cities; 32nd of 38 in Texas
- Wet days96th driest of 378
- Comfortable days268th most of 342
What to pack for McKinney in September
- Light, breathable clothing – highs near 88°F and about 14 muggy days
Heating and cooling
September has 5 heating degree days and 362 cooling degree days (base 65°F), 7% of the year's total heating and cooling demand.
Questions
How hot is McKinney in September?
The normal high is 88°F and the normal low is 66°F. From 1991 to 2020 the hottest September reading was 112°F (September 4, 2000).
Does it rain a lot in McKinney in September?
About 6 days in September have at least 0.01 in of precipitation, and the normal total is 2.9 in. The wettest September in 1991-2020 was in 2018 (13.2 in); the driest was in 2019, with no measurable precipitation.
Is September a good time to visit McKinney?
September ranks 9th of 12 months on our comfort score for McKinney (43 out of 100). It has about 2 comfortable days and about 15 days at 90°F or hotter. The best months are March and April.
Where the numbers come from
- Temperature and frost dates: Mckinney Muni Airport (USW00053914), 1.9 mi SE of the city center, 580 ft (50 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Rain, snowfall and snow depth: Frisco (USC00413370), 10 mi W of the city center, 747 ft (117 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Dallas Ft Worth Airport (USW00003927), 31 mi SW of the city center, 560 ft (70 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Dallas/Ft Worth International Airport (722590-03927), 31 mi SW of the city center, 544 ft (86 ft lower than the city). Hourly observations, 1991-2020.