Hourly Weather | Today Tuesday, July 21, 2026
Active Weather Warnings
Seattle, Washington
1 AM
Cloudy Night
66°
Feels Like 63°
0
Humidity: 78%
UV Index: 0
Wind: 6 mph
2 AM
Cloudy Night
64°
Feels Like 64°
0
Humidity: 76%
UV Index: 0
Wind: 6 mph
3 AM
Cloudy Night
64°
Feels Like 64°
0
Humidity: 78%
UV Index: 0
Wind: 5 mph
4 AM
Cloudy Night
64°
Feels Like 64°
0
Humidity: 78%
UV Index: 0
Wind: 5 mph
5 AM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 80%
UV Index: 0
Wind: 4 mph
6 AM
Cloudy Weather
63°
Feels Like 64°
0
Humidity: 81%
UV Index: 0
Wind: 4 mph
7 AM
Cloudy Weather
64°
Feels Like 66°
0
Humidity: 77%
UV Index: 1
Wind: 4 mph
8 AM
Cloudy Weather
68°
Feels Like 70°
0
Humidity: 69%
UV Index: 2
Wind: 4 mph
9 AM
Cloudy Weather
72°
Feels Like 75°
0
Humidity: 62%
UV Index: 3
Wind: 5 mph
10 AM
Cloudy Weather
75°
Feels Like 79°
0
Humidity: 55%
UV Index: 4
Wind: 6 mph
11 AM
Cloudy Weather
79°
Feels Like 82°
0
Humidity: 49%
UV Index: 6
Wind: 7 mph
12 PM
Cloudy Weather
81°
Feels Like 88°
0
Humidity: 44%
UV Index: 8
Wind: 7 mph
1 PM
Cloudy Weather
84°
Feels Like 90°
0
Humidity: 39%
UV Index: 8
Wind: 7 mph
2 PM
Cloudy Weather
86°
Feels Like 91°
0
Humidity: 36%
UV Index: 8
Wind: 7 mph
3 PM
Cloudy Weather
88°
Feels Like 91°
0
Humidity: 34%
UV Index: 6
Wind: 8 mph
4 PM
Cloudy Weather
90°
Feels Like 91°
0
Humidity: 32%
UV Index: 4
Wind: 8 mph
5 PM
Cloudy Weather
88°
Feels Like 90°
0
Humidity: 33%
UV Index: 3
Wind: 8 mph
6 PM
Cloudy Weather
88°
Feels Like 88°
0
Humidity: 33%
UV Index: 2
Wind: 8 mph
7 PM
Cloudy Weather
84°
Feels Like 82°
0
Humidity: 36%
UV Index: 1
Wind: 8 mph
8 PM
Cloudy Weather
82°
Feels Like 81°
0
Humidity: 40%
UV Index: 0
Wind: 7 mph
9 PM
Cloudy Night
81°
Feels Like 77°
0
Humidity: 43%
UV Index: 0
Wind: 7 mph
10 PM
Cloudy Night
77°
Feels Like 75°
0
Humidity: 48%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Night
73°
Feels Like 72°
0
Humidity: 53%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

1 AM
35 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.45 µg/m³
  • PM10: 10.8 µg/m³
  • O3: 0.013 ppm
  • NO2: 3.4 ppb
  • SO2: 0.2 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

2 AM
35 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.35 µg/m³
  • PM10: 10.85 µg/m³
  • O3: 0.011 ppm
  • NO2: 3.3 ppb
  • SO2: 0.2 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

3 AM
34 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.2 µg/m³
  • PM10: 10.79 µg/m³
  • O3: 0.010 ppm
  • NO2: 3.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

4 AM
34 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.18 µg/m³
  • PM10: 10.85 µg/m³
  • O3: 0.010 ppm
  • NO2: 3.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

5 AM
35 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.42 µg/m³
  • PM10: 11.13 µg/m³
  • O3: 0.009 ppm
  • NO2: 3.4 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

6 AM
35 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.48 µg/m³
  • PM10: 11.15 µg/m³
  • O3: 0.009 ppm
  • NO2: 3.7 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

7 AM
35 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.36 µg/m³
  • PM10: 11.01 µg/m³
  • O3: 0.008 ppm
  • NO2: 4.4 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

8 AM
34 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.15 µg/m³
  • PM10: 10.79 µg/m³
  • O3: 0.009 ppm
  • NO2: 4.4 ppb
  • SO2: 0.3 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

9 AM
33 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 7.86 µg/m³
  • PM10: 10.28 µg/m³
  • O3: 0.011 ppm
  • NO2: 4 ppb
  • SO2: 0.3 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

10 AM
31 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 7.55 µg/m³
  • PM10: 9.75 µg/m³
  • O3: 0.014 ppm
  • NO2: 3.6 ppb
  • SO2: 0.3 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

11 AM
32 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 7.6 µg/m³
  • PM10: 9.57 µg/m³
  • O3: 0.020 ppm
  • NO2: 3 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

12 PM
54 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 13.71 µg/m³
  • PM10: 15.19 µg/m³
  • O3: 0.050 ppm
  • NO2: 1.6 ppb
  • SO2: 1.2 ppb
  • CO: 0.12 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

1 PM
74 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 16.34 µg/m³
  • PM10: 17.61 µg/m³
  • O3: 0.062 ppm
  • NO2: 1 ppb
  • SO2: 1.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

2 PM
87 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 16.52 µg/m³
  • PM10: 17.67 µg/m³
  • O3: 0.066 ppm
  • NO2: 0.9 ppb
  • SO2: 1.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

3 PM
101 AQI
Unhealthy air quality for sensitive groups Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 18.53 µg/m³
  • PM10: 19.44 µg/m³
  • O3: 0.070 ppm
  • NO2: 0.8 ppb
  • SO2: 1.2 ppb
  • CO: 0.11 ppm

Health Recommendations:

Members of sensitive groups may experience health effects. The general public is less likely to be affected.

4 PM
98 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 18.26 µg/m³
  • PM10: 19.07 µg/m³
  • O3: 0.070 ppm
  • NO2: 0.8 ppb
  • SO2: 0.9 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

5 PM
90 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 16.36 µg/m³
  • PM10: 17.2 µg/m³
  • O3: 0.067 ppm
  • NO2: 0.8 ppb
  • SO2: 0.8 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

6 PM
69 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 13.45 µg/m³
  • PM10: 14.44 µg/m³
  • O3: 0.060 ppm
  • NO2: 1.1 ppb
  • SO2: 0.7 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

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

Pollutant Concentrations:

  • PM2.5: 10.34 µg/m³
  • PM10: 11.57 µg/m³
  • O3: 0.051 ppm
  • NO2: 1.3 ppb
  • SO2: 0.5 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 8 µg/m³
  • PM10: 9.45 µg/m³
  • O3: 0.043 ppm
  • NO2: 1.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 6.81 µg/m³
  • PM10: 8.37 µg/m³
  • O3: 0.032 ppm
  • NO2: 2.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

10 PM
27 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 6.49 µg/m³
  • PM10: 8.2 µg/m³
  • O3: 0.023 ppm
  • NO2: 2.9 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

11 PM
26 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 6.32 µg/m³
  • PM10: 8.22 µg/m³
  • O3: 0.017 ppm
  • NO2: 3.4 ppb
  • SO2: 0.1 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

Weather Alerts and Warnings for Seattle

Moderate Expected Likely

Heat Advisory

Heat Advisory issued July 20 at 8:49PM PDT until July 22 at 11:00PM PDT by NWS Seattle WA
Jul 21, 10:00 AM Jul 22, 11:00 PM
WHAT: Hot conditions with high temperatures up to 95 degrees
expected and low temperatures from 60 to 65 degrees. This will
pose a moderate to major risk of heat-related illness.

WHERE: Eastern Kitsap County, City of Seattle, Downtown Everett /
Marysville Area, Eastside, Foothills and Valleys of Central King
County, Foothills and Valleys of Pierce and Southern King
Counties, Foothills and Valleys of Snohomish and Northern King
Counties, Lowlands of Pierce and Southern King Counties, and
Shoreline / Lynnwood / South Everett Area.

WHEN: From 10 AM Tuesday to 11 PM PDT Wednesday.

IMPACTS: Heat will significantly increase the risk of
heat-related illnesses for those who are sensitive to heat,
especially those without effective cooling or adequate hydration.

ADDITIONAL DETAILS: Areas closest to the water will experience
cooler daytime high temperatures.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, 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 9 1 1. For sheltering information and other human services in your area, dial 2 1 1 during business hours or visit wa211.org anytime.
Updated: Jul 21, 12:14 AM Source: NWS Alert