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Today | Weather | Thursday, December 4, 2025
Active Weather Warnings

Weather in Hayward, California

01:30 AM
Now
Cloudy Night
43° F
Feels Like 43°
Precipitation 0 %
Wind 5 mph
Humidity 89 %
Today
Cloudy Weather
Day 59°
Night 39°
Precipitation 1 %
Wind 6 mph
UV Index (0 - 11+) 2

Hayward Weather Forecast Updated

23 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 4, 2024)
Cloudy Night

Day

68°

Night

46°

Wind

4 mph

Precipitation

0 %

Air Quality in Hayward

NOW
26 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 5.48 µg/m³
PM10 11.42 µg/m³
O3 0.028 ppm
NO2 5.8 ppb
SO2 0.4 ppb
CO 0.16 ppm
NH3 0.25 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

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

Show raw pollutant concentrations (µg/m³)
PM2.5 – 5.48 µg/m³
PM10 – 11.42 µg/m³
O3 – 55.69 µg/m³
NO2 – 10.86 µg/m³
SO2 – 1.14 µg/m³
CO – 185.85 µg/m³
NH3 – 0.25 µg/m³
NO – 0 µg/m³
View Hourly Air Quality Forecast

Weather Alerts and Warnings for Hayward

Minor Expected Likely

Coastal Flood Advisory

Coastal Flood Advisory issued December 3 at 9:39PM PST until December 7 at 3:00PM PST by NWS San Francisco CA
Dec 3, 9:39 PM → Dec 7, 3:00 PM
WHAT: Up to 1.4 ft of inundation above ground level is
possible in low lying areas near shorelines and tidal
waterways.

WHERE: Bayshore locations along the San Francisco Bay and San
Pablo Bay.

WHEN: Until 3 PM PST Sunday.

IMPACTS: Flooding of lots, parks, and roads with only
isolated road closures expected.

ADDITIONAL DETAILS: At the San Francisco tidal gauge high
tide is expected to be 1.2 ft above normal (7.00 ft MLLW) at
9:04 AM Wednesday, 1.4 ft above normal (7.20 ft MLLW) at 9:48
AM Thursday, 1.4 ft above normal (7.23 ft MLLW) at 10:35 AM
Friday, 1.2 ft above normal (7.08 ft MLLW) at 11:25 AM
Saturday, and 0.9 ft above normal (6.75 ft MLLW) at 12:17 PM
Sunday. High tide timing varies up to 90 minutes earlier or
later along the Pacific Coast and throughout the San Francisco
Bay respectively.
+ Read More
If travel is required, allow extra time as some roads may be closed. Do not drive around barricades or through water of unknown depth. Take the necessary actions to protect flood-prone property.
Updated: Dec 4, 1:07 AM Source: NWS Alert