Today | Weather | Wednesday, September 9, 2026

Active Weather Warnings

Red Flag Warning

Weather in Casper, Wyoming

07:05 PM

Now

79° F

Feels Like 75°

Precipitation 0 %

Wind 9 mph

UV Index (0 - 11+) 0

Humidity 9 %

Today

Day 82°

Night 45°

Precipitation 0 %

Wind 8 mph

UV Index (0 - 11+) 6

Casper Weather Forecast Updated

16 minutes ago

Last updated on September 09, 2026 at 6:49 PM

Air Quality in Casper

NOW

49 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 0.53 µg/m³

PM₁₀ 1.03 µg/m³

O₃ 0.052 ppm

NO₂ 0.4 ppb

SO₂ 0.1 ppb

CO 0.07 ppm

NH₃ 0.56 µg/m³

NO 0.03 µg/m³

PM_2.5 – 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)

PM_2.5 – 0.53 µg/m³

PM₁₀ – 1.03 µg/m³

O₃ – 103.05 µg/m³

NO₂ – 0.81 µg/m³

SO₂ – 0.34 µg/m³

CO – 80.11 µg/m³

NH₃ – 0.56 µg/m³

NO – 0.03 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Casper

Severe Expected Likely

Red Flag Warning

Red Flag Warning issued September 9 at 12:58PM MDT until September 10 at 9:00PM MDT by NWS Riverton WY

Sep 9, 12:58 PM → Sep 10, 9:00 PM

* AFFECTED AREA:
In Central WY...Fire Weather Zones 280...289 and 300.

* COUNTIES AFFECTED:
In Central WY...Fremont...Natrona.
In Southwest WY...Sweetwater.

* IMPACTS: Low Humidities and Strong Gusty Winds could cause
erratic fire behavior.

* WIND: West 12 to 18 mph with gusts up to 25 to 30 mph. Thursday,
west to southwest 15 to 20 mph with gusts up to 35 to 40 mph.

* HUMIDITY: As low as 8 percent. Thursday, as low as 6 to 8
percent. RH recovery will be poor tonight.

+ Read More

A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior.

Updated: Sep 9, 6:49 PM Source: NWS Alert