Hourly Weather Forecast for Santa Clara, California

Hourly Weather | Today › Wednesday, March 18, 2026

Active Weather Warnings

Heat Advisory

Santa Clara, California

6 AM

63°

Feels Like 61°

Humidity: 61%

UV Index: 0

Wind: 5 mph

7 AM

63°

Feels Like 63°

Humidity: 63%

UV Index: 0

Wind: 5 mph

8 AM

64°

Feels Like 64°

Humidity: 59%

UV Index: 1

Wind: 5 mph

9 AM

68°

Feels Like 70°

Humidity: 56%

UV Index: 2

Wind: 5 mph

10 AM

73°

Feels Like 77°

Humidity: 48%

UV Index: 3

Wind: 5 mph

11 AM

81°

Feels Like 82°

Humidity: 41%

UV Index: 4

Wind: 6 mph

12 PM

82°

Feels Like 88°

Humidity: 36%

UV Index: 5

Wind: 6 mph

1 PM

86°

Feels Like 90°

Humidity: 32%

UV Index: 5

Wind: 7 mph

2 PM

90°

Feels Like 91°

Humidity: 29%

UV Index: 5

Wind: 7 mph

3 PM

91°

Feels Like 93°

Humidity: 27%

UV Index: 4

Wind: 8 mph

4 PM

93°

Feels Like 93°

Humidity: 25%

UV Index: 3

Wind: 9 mph

5 PM

91°

Feels Like 91°

Humidity: 27%

UV Index: 2

Wind: 9 mph

6 PM

90°

Feels Like 88°

Humidity: 31%

UV Index: 1

Wind: 8 mph

7 PM

86°

Feels Like 82°

Humidity: 36%

UV Index: 0

Wind: 8 mph

8 PM

82°

Feels Like 81°

Humidity: 41%

UV Index: 0

Wind: 7 mph

9 PM

81°

Feels Like 77°

Humidity: 46%

UV Index: 0

Wind: 6 mph

10 PM

77°

Feels Like 75°

Humidity: 50%

UV Index: 0

Wind: 5 mph

11 PM

73°

Feels Like 72°

Humidity: 55%

UV Index: 0

Wind: 4 mph

Hourly Air Quality Forecast - AQI (US EPA)

6 AM

37 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.87 µg/m³
PM₁₀: 16.97 µg/m³
O₃: 0.035 ppm
NO₂: 2.7 ppb
SO₂: 0.4 ppb
CO: 0.15 ppm

Health Recommendations:

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

7 AM

37 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.98 µg/m³
PM₁₀: 17.01 µg/m³
O₃: 0.034 ppm
NO₂: 2.7 ppb
SO₂: 0.4 ppb
CO: 0.15 ppm

Health Recommendations:

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

8 AM

36 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.66 µg/m³
PM₁₀: 16.45 µg/m³
O₃: 0.033 ppm
NO₂: 2.7 ppb
SO₂: 0.4 ppb
CO: 0.15 ppm

Health Recommendations:

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

9 AM

35 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.4 µg/m³
PM₁₀: 15.94 µg/m³
O₃: 0.033 ppm
NO₂: 2.6 ppb
SO₂: 0.4 ppb
CO: 0.14 ppm

Health Recommendations:

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

10 AM

35 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.32 µg/m³
PM₁₀: 15.68 µg/m³
O₃: 0.034 ppm
NO₂: 2.3 ppb
SO₂: 0.4 ppb
CO: 0.14 ppm

Health Recommendations:

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

11 AM

35 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.3 µg/m³
PM₁₀: 15.61 µg/m³
O₃: 0.037 ppm
NO₂: 2 ppb
SO₂: 0.4 ppb
CO: 0.14 ppm

Health Recommendations:

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

12 PM

37 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 8.58 µg/m³
PM₁₀: 15.98 µg/m³
O₃: 0.040 ppm
NO₂: 1.7 ppb
SO₂: 0.4 ppb
CO: 0.13 ppm

Health Recommendations:

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

1 PM

41 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.27 µg/m³
PM₁₀: 16.93 µg/m³
O₃: 0.044 ppm
NO₂: 1.4 ppb
SO₂: 0.4 ppb
CO: 0.13 ppm

Health Recommendations:

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

2 PM

43 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.92 µg/m³
PM₁₀: 17.81 µg/m³
O₃: 0.047 ppm
NO₂: 1.2 ppb
SO₂: 0.4 ppb
CO: 0.12 ppm

Health Recommendations:

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

3 PM

46 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.98 µg/m³
PM₁₀: 17.91 µg/m³
O₃: 0.049 ppm
NO₂: 1.1 ppb
SO₂: 0.4 ppb
CO: 0.12 ppm

Health Recommendations:

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

4 PM

48 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.8 µg/m³
PM₁₀: 17.83 µg/m³
O₃: 0.051 ppm
NO₂: 0.8 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

5 PM

49 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.62 µg/m³
PM₁₀: 17.85 µg/m³
O₃: 0.053 ppm
NO₂: 0.7 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

6 PM

49 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 9.36 µg/m³
PM₁₀: 17.79 µg/m³
O₃: 0.053 ppm
NO₂: 0.8 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

7 PM

48 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 8.92 µg/m³
PM₁₀: 17.35 µg/m³
O₃: 0.052 ppm
NO₂: 0.9 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

8 PM

47 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 8.4 µg/m³
PM₁₀: 16.62 µg/m³
O₃: 0.051 ppm
NO₂: 1.1 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

9 PM

46 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 8.14 µg/m³
PM₁₀: 16.05 µg/m³
O₃: 0.049 ppm
NO₂: 1.2 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

10 PM

45 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 8.03 µg/m³
PM₁₀: 15.7 µg/m³
O₃: 0.048 ppm
NO₂: 1.3 ppb
SO₂: 0.4 ppb
CO: 0.11 ppm

Health Recommendations:

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

11 PM

44 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 7.82 µg/m³
PM₁₀: 15.23 µg/m³
O₃: 0.047 ppm
NO₂: 1.5 ppb
SO₂: 0.4 ppb
CO: 0.12 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 Santa Clara

Moderate Expected Likely

Heat Advisory

Heat Advisory issued March 17 at 10:21PM PDT until March 20 at 8:00PM PDT by NWS San Francisco CA

Mar 17, 10:21 PM → Mar 20, 8:00 PM

WHAT: High temperatures in the low to mid 90s across the interior
and 80s along the coastline.

WHERE: The Bay Area and Central Coast.

WHEN: Until 8 PM PDT Friday.

IMPACTS: This level of heat affects most individuals sensitive to
heat, especially those without effective cooling and/or adequate
hydration. Impacts possible in some health systems and in
heat-sensitive industries. Hot conditions can cause heat illnesses.

ADDITIONAL DETAILS: Much above normal temperatures in the upper
80s to mid 90s are expected through the remainder of the week
across the Bay Area and Central Coast. Portions of the interior
Central Coast may reach the upper 90s starting mid to late week.
Overnight lows in the upper 50s to low 60s will offer some relief
to the lower elevations but will offer minimal relief within the
higher elevations. Conditions will be much above normal along the
coast this week but coastal residents may experience more relief
overnight than those across the interior. The risk of heat related
illnesses will increase with each additional day of heating from
this event.

+ 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: Mar 18, 4:45 AM Source: NWS Alert

Hourly Air Quality Forecast - AQI (US EPA)

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Weather Alerts and Warnings for Santa Clara

Heat Advisory

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