Today | Weather | Friday, September 18, 2026
Active Weather Warnings

Weather in Decatur, Alabama

07:33 AM
Now
Sunny Weather
73° F
Feels Like 79°
Precipitation 0 %
Wind 4 mph
UV Index (0 - 11+) 1
Humidity 83 %
Today
Hot Day
Day 99°
Night 70°
Precipitation 25 %
Wind 4 mph
UV Index (0 - 11+) 7

Decatur Weather Forecast Updated

18 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 18, 2025)

Day

93°

Night

63°

Air Quality in Decatur

NOW
42 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 10 µg/m³
PM10 12.83 µg/m³
O3 0.008 ppm
NO2 1.8 ppb
SO2 0.1 ppb
CO 0.12 ppm
NH3 1.08 µg/m³
NO 0.44 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)
PM2.510 µg/m³
PM1012.83 µg/m³
O316.51 µg/m³
NO23.44 µg/m³
SO20.19 µg/m³
CO143.04 µg/m³
NH31.08 µg/m³
NO0.44 µg/m³

Weather Alerts and Warnings for Decatur

Moderate Expected Likely

Heat Advisory

Heat Advisory issued September 17 at 12:01PM CDT until September 19 at 8:00PM CDT by NWS Huntsville AL
Sep 17, 12:01 PM Sep 19, 8:00 PM
WHAT: Heat index values of up to 100 to 105.

WHERE: All of north Alabama and southern middle Tennessee.

WHEN: Until 8 PM CDT Saturday.

IMPACTS: Hot temperatures and high humidity may cause heat
illnesses.
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Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke.
Updated: Sep 18, 7:14 AM Source: NWS Alert