Today | Weather | Tuesday, September 8, 2026
Active Weather Warnings

Weather in McKinney, Texas

04:01 AM
Now
Night
81° F
Feels Like 88°
Precipitation 7 %
Wind 5 mph
Humidity 74 %
Today
Sunny Weather
Day 99°
Night 77°
Precipitation 25 %
Wind 9 mph
UV Index (0 - 11+) 8

Warning: High UV Index Today: 8

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

McKinney Weather Forecast Updated

11 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 8, 2025)
Night

Day

82°

Night

57°

Wind

5 mph

Precipitation

0 %

Air Quality in McKinney

NOW
27 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.44 µg/m³
PM10 3.77 µg/m³
O3 0.030 ppm
NO2 0.9 ppb
SO2 0.4 ppb
CO 0.09 ppm
NH3 0.68 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.52.44 µg/m³
PM103.77 µg/m³
O358.11 µg/m³
NO21.74 µg/m³
SO21.16 µg/m³
CO105.46 µg/m³
NH30.68 µg/m³
NO0 µg/m³

Weather Alerts and Warnings for McKinney

Moderate Expected Likely

Heat Advisory

Heat Advisory issued September 8 at 12:01AM CDT until September 8 at 8:00PM CDT by NWS Fort Worth TX
Sep 8, 12:01 AM Sep 8, 8:00 PM
WHAT: Heat index values up to 108.

WHERE: Portions of North Texas

WHEN: Until 8 PM CDT Tuesday.

IMPACTS: Hot temperatures and high humidity will increase the risk
for heat-related illnesses to occur, particularly for those working
or participating in outdoor activities.
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Take extra precautions when outside by staying hydrated, wearing lightweight and loose fitting clothing, and limiting strenuous activities to the early morning or evening. Check up on relatives and neighbors. Never leave young children or pets in an enclosed vehicle, even for a short time, as temperatures can quickly rise to life-threatening levels. Know the signs and symptoms of heat exhaustion and heat stroke. To reduce risk when outdoors, the occupational safety and health administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 911 ASAP if you or someone you know is exhibiting signs of heat stroke.
Updated: Sep 8, 3:49 AM Source: NWS Alert