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Hourly Weather | Today › Wednesday, March 18, 2026
Active Weather Warnings
Fort Collins, Colorado
11 AM
Cloudy Weather
64°
Feels Like 68°
0
Humidity: 22%
UV Index: 4
Wind: 8 mph
12 PM
Cloudy Weather
72°
Feels Like 73°
0
Humidity: 17%
UV Index: 5
Wind: 9 mph
1 PM
Cloudy Weather
75°
Feels Like 77°
0
Humidity: 14%
UV Index: 5
Wind: 12 mph
2 PM
Cloudy Weather
79°
Feels Like 79°
0
Humidity: 12%
UV Index: 5
Wind: 13 mph
3 PM
Cloudy Weather
81°
Feels Like 81°
0
Humidity: 10%
UV Index: 4
Wind: 14 mph
4 PM
Cloudy Weather
82°
Feels Like 81°
0
Humidity: 10%
UV Index: 3
Wind: 14 mph
5 PM
Cloudy Weather
81°
Feels Like 79°
0
Humidity: 11%
UV Index: 2
Wind: 14 mph
6 PM
Cloudy Weather
77°
Feels Like 75°
0
Humidity: 12%
UV Index: 1
Wind: 14 mph
7 PM
Cloudy Weather
72°
Feels Like 68°
0
Humidity: 15%
UV Index: 0
Wind: 12 mph
8 PM
Cloudy Night
72°
Feels Like 68°
0
Humidity: 16%
UV Index: 0
Wind: 9 mph
9 PM
Cloudy Night
66°
Feels Like 64°
0
Humidity: 19%
UV Index: 0
Wind: 8 mph
10 PM
Night
64°
Feels Like 63°
0
Humidity: 21%
UV Index: 0
Wind: 8 mph
11 PM
Night
61°
Feels Like 57°
0
Humidity: 24%
UV Index: 0
Wind: 8 mph

Hourly Air Quality Forecast - AQI (US EPA)

11 AM
34 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.88 µg/m³
  • PM10: 1.38 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.6 ppb
  • SO2: 0.2 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

12 PM
34 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.89 µg/m³
  • PM10: 1.33 µg/m³
  • O3: 0.037 ppm
  • NO2: 0.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

1 PM
38 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.69 µg/m³
  • PM10: 0.97 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.2 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

2 PM
38 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.67 µg/m³
  • PM10: 0.9 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.1 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

3 PM
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.68 µg/m³
  • PM10: 0.89 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.1 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

4 PM
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.69 µg/m³
  • PM10: 0.9 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.1 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

5 PM
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.74 µg/m³
  • PM10: 0.96 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.2 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

6 PM
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.78 µg/m³
  • PM10: 1.01 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.3 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

7 PM
37 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.82 µg/m³
  • PM10: 1.06 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.7 ppb
  • SO2: 0.1 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

8 PM
35 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.87 µg/m³
  • PM10: 1.14 µg/m³
  • O3: 0.037 ppm
  • NO2: 1.2 ppb
  • SO2: 0.1 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

9 PM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.91 µg/m³
  • PM10: 1.21 µg/m³
  • O3: 0.036 ppm
  • NO2: 1.4 ppb
  • SO2: 0.1 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

10 PM
32 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.91 µg/m³
  • PM10: 1.22 µg/m³
  • O3: 0.035 ppm
  • NO2: 1.4 ppb
  • SO2: 0.1 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

11 PM
32 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.91 µg/m³
  • PM10: 1.24 µg/m³
  • O3: 0.035 ppm
  • NO2: 1.4 ppb
  • SO2: 0.1 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

Current Real-Time Air Quality Report

Weather Alerts and Warnings for Fort Collins

Severe Future Possible

Fire Weather Watch

Fire Weather Watch issued March 17 at 2:16AM MDT until March 18 at 7:00PM MDT by NWS Denver CO
Mar 18, 12:00 PM → Mar 18, 7:00 PM
* AFFECTED AREA...Fire Weather Zones 238, 242, 244, 248, 249,
250 and 251.

* TIMING...For the Red Flag Warning, from 10 AM this morning to
8 PM MDT this evening. For the Fire Weather Watch, from
Wednesday afternoon through Wednesday evening.

* WINDS...Northwest 20 to 30 mph with gusts up to 45 mph.

* RELATIVE HUMIDITY...As low as 14 percent. On Wednesday, as low
as 11 percent.

IMPACTS: Conditions will be favorable for rapid fire spread.
Avoid outdoor burning and any activity that may produce a
spark and start a wildfire.
+ 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. A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings.
Updated: Mar 17, 12:05 PM Source: NWS Alert
Severe Expected Likely

Red Flag Warning

Red Flag Warning issued March 18 at 3:36AM MDT until March 18 at 7:00PM MDT by NWS Denver CO
Mar 18, 11:00 AM → Mar 18, 7:00 PM
* AFFECTED AREA...Fire Weather Zones 238 and 242.

* TIMING...For the Red Flag Warning, from 11 AM this morning to
7 PM MDT this evening. For the Fire Weather Watch, from
Thursday morning through Thursday evening.

* WINDS...Northwest 15 to 25 mph with gusts up to 40 mph. On
Thursday, northwest wind gusts up to 30 mph.

* RELATIVE HUMIDITY...As low as 8 percent both days.

IMPACTS: Conditions will be favorable for rapid fire spread.
Avoid outdoor burning and any activity that may produce a
spark and start a wildfire.
+ 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. A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings.
Updated: Mar 18, 9:04 AM Source: NWS Alert

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