Hourly Weather | Today › Sunday, October 4, 2026
Active Weather Warnings
Sunnyvale, California
3 PM
Cloudy Weather
95°
Feels Like 95°
0
Humidity: 27%
UV Index: 4
Wind: 9 mph
4 PM
Cloudy Weather
93°
Feels Like 91°
0
Humidity: 29%
UV Index: 3
Wind: 9 mph
5 PM
Cloudy Weather
90°
Feels Like 90°
0
Humidity: 33%
UV Index: 2
Wind: 9 mph
6 PM
Cloudy Weather
88°
Feels Like 84°
0
Humidity: 37%
UV Index: 1
Wind: 8 mph
7 PM
Cloudy Night
84°
Feels Like 82°
0
Humidity: 41%
UV Index: 0
Wind: 6 mph
8 PM
Cloudy Night
82°
Feels Like 81°
0
Humidity: 45%
UV Index: 0
Wind: 4 mph
9 PM
Cloudy Night
81°
Feels Like 79°
0
Humidity: 49%
UV Index: 0
Wind: 4 mph
10 PM
Cloudy Night
77°
Feels Like 75°
0
Humidity: 52%
UV Index: 0
Wind: 2 mph
11 PM
Night
73°
Feels Like 72°
0
Humidity: 57%
UV Index: 0
Wind: 2 mph

Hourly Air Quality Forecast - AQI (US EPA)

3 PM
36 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.74 µg/m³
  • PM10: 18.76 µg/m³
  • O3: 0.038 ppm
  • NO2: 0.5 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

4 PM
37 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.88 µg/m³
  • PM10: 19.25 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.5 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 8.93 µg/m³
  • PM10: 19.35 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.5 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 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: 8.89 µg/m³
  • PM10: 19.1 µg/m³
  • O3: 0.042 ppm
  • NO2: 0.6 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 PM
38 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 8.82 µg/m³
  • PM10: 18.76 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

8 PM
37 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.78 µg/m³
  • PM10: 18.46 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.9 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

9 PM
37 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 8.85 µg/m³
  • PM10: 18.43 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.9 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
38 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.03 µg/m³
  • PM10: 18.73 µg/m³
  • O3: 0.038 ppm
  • NO2: 1 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.29 µg/m³
  • PM10: 19.18 µg/m³
  • O3: 0.038 ppm
  • NO2: 1 ppb
  • SO2: 0.4 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 Sunnyvale

Moderate Expected Likely

Heat Advisory

Heat Advisory issued October 3 at 7:48PM PDT until October 7 at 10:00PM PDT by NWS San Francisco CA
Oct 3, 7:48 PM → Oct 7, 10:00 PM
WHAT: Hot conditions with maximum temperatures in the mid-90s to
low-100s. Mild minimum temperatures and weak onshore flow will
limit overnight relief.

WHERE: The East Bay and San Francisco Bay Shoreline, North Bay
Interior Mountains and Valleys, The Santa Clara Valley and Eastern
Hills, The Santa Cruz Mountains, Interior Monterey County and the
Santa Lucia Range, Most of San Benito County and the Cholame Hills
in Southeast Monterey County, and Southern Salinas Valley/Arroyo
Seco and Lake San Antonio.

WHEN: Until 10 PM PDT Wednesday.

IMPACTS: This level of heat affects anyone without effective
cooling and/or adequate hydration. Impacts likely in some health
systems, heat-sensitive industries and infrastructure.
+ Read More
Hydration is a critical piece to surviving the heat. Drink water, and if possible, take water to those who are vulnerable. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to the early morning or evening. Take action when you experience symptoms of heat exhaustion and/or heat stroke. Beat the heat and check the backseat! Do not leave young children or pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes.
Updated: Oct 4, 12:47 PM Source: NWS Alert