Today | Weather | Monday, October 12, 2026

Active Weather Warnings

Dense Fog Advisory

Weather in Helena, Montana

07:07 PM

Now

36° F

Feels Like 34°

Precipitation 0 %

Wind 4 mph

Humidity 72 %

Today

Day 39°

Night 25°

Precipitation 1 %

Wind 4 mph

UV Index (0 - 11+) 3

FROST FORECAST

Tomorrow Morning Frost 12 AM – 9 AM

Helena Weather Forecast Updated

Air Quality in Helena

NOW

19 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 1.12 µg/m³

PM₁₀ 1.14 µg/m³

O₃ 0.021 ppm

NO₂ 2.7 ppb

SO₂ 0 ppb

CO 0.13 ppm

NH₃ 1.27 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 – 1.12 µg/m³

PM₁₀ – 1.14 µg/m³

O₃ – 40.98 µg/m³

NO₂ – 5.12 µg/m³

SO₂ – 0.02 µg/m³

CO – 148.59 µg/m³

NH₃ – 1.27 µg/m³

NO – 0.03 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Helena

Moderate Expected Likely

Dense Fog Advisory

Dense Fog Advisory issued October 12 at 12:25PM MDT until October 13 at 12:00PM MDT by NWS Great Falls MT

Oct 12, 9:00 PM → Oct 13, 12:00 PM

WHAT: Visibility as low as one quarter of a mile in dense fog.

WHERE: Portions of central, north central, and southwest Montana.

WHEN: From 9 PM this evening to noon MDT Tuesday.

IMPACTS: Low visibility could make driving conditions hazardous.

ADDITIONAL DETAILS: Below freezing temperatures may lead to a
glaze of ice on surfaces, most notably on bridges and overpasses.

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If driving, slow down, use your headlights, and leave plenty of distance ahead of you.

Updated: Oct 12, 4:16 PM Source: NWS Alert