Today | Weather | Sunday, September 14, 2025

Weather in Sunnyvale, California

08:19 PM
Now
Cloudy Night
70° F
Feels Like 68°
Precipitation 0 %
Wind 8 mph
Humidity 72 %
Today
Cloudy Weather
Day 81°
Night 57°
Precipitation 1 %
Wind 13
UV Index (0 - 11+) 11

Warning: Extreme UV Index Today: 11+

Overexposure to the sun's harmful UV rays can cause sunburn and increase the risk of developing skin cancer, including melanoma. Protect yourself by wearing clothing that covers your skin, sunglasses, and a hat. Apply a broad-spectrum sunscreen with an SPF of 30 or higher every two hours, even on cloudy days. Minimize direct sun exposure during peak hours (10 AM to 4 PM) to reduce the risk.

Other:

Mostly bright and clear.

Sunnyvale Weather Forecast Updated

Weather Forecast History

Last Year's Weather on This Day (September 14, 2024)

Cloudy Weather

Day

79°

Night

57°

Wind

7 mph

UV Index

6

Precipitation

0

Air quality in Sunnyvale

NOW
39 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 6.37 µg/m³
PM10 7.67 µg/m³
O₃ 18.20 ppb
NO₂ 8.12 ppb
SO₂ 0.99 ppb
CO 129.19 ppb
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide

Health Recommendations:

With this level of air quality, you have no limitations. Enjoy the outdoors