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Active Weather Warnings

Weather in Rancho Cucamonga, California

02:02 PM
Now
Rainy Weather
61° F
Feels Like 57°
Precipitation 60 %
Wind 6 mph
UV Index (0 - 11+) 1
Humidity 84 %
Today
Rainy Weather
Day 63°
Night 52°
Precipitation 100 %
Wind 5 mph
UV Index (0 - 11+) 1

Rancho Cucamonga Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (January 1, 2025)
Sunny Weather

Day

73°

Night

48°

Wind

4 mph

UV Index

3

Precipitation

0 %

Air Quality in Rancho Cucamonga

NOW
34 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.38 µg/m³
PM10 3.49 µg/m³
O3 0.036 ppm
NO2 0.2 ppb
SO2 0.1 ppb
CO 0.11 ppm
NH3 0 µg/m³
NO 0.05 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)
PM2.52.38 µg/m³
PM103.49 µg/m³
O371.61 µg/m³
NO20.41 µg/m³
SO20.24 µg/m³
CO123.94 µg/m³
NH30 µg/m³
NO0.05 µg/m³

Weather Alerts and Warnings for Rancho Cucamonga

Severe Future Possible

Flood Watch

Flood Watch issued January 1 at 12:16PM PST until January 1 at 10:00PM PST by NWS San Diego CA
Jan 1, 12:16 PM Jan 1, 10:00 PM
WHAT: Flooding caused by excessive rainfall continues to be
possible.

WHERE: A portion of Southwest California, including the following
areas, Orange County Coastal Areas, Orange County Inland Areas,
San Bernardino County Mountains, San Bernardino and Riverside
County Valleys-The Inland Empire and Santa Ana Mountains and
Foothills.

WHEN: Until 10 PM PST this evening.

IMPACTS: Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Flooding may occur in poor drainage and urban areas. Low-water
crossings may be flooded. Minor flooding and debris flows possible
in and below recent burn scars.

ADDITIONAL DETAILS:
- A warm low pressure system from the southwest will bring
periods of moderate to locally heavy precipitation through
Thursday evening. The heaviest showers occurred this morning.
High soil moisture from last week's heavy rainfall and will
exacerbate the flooding threat in the watch area.
- https://www.weather.gov/safety/flood
+ Read More
You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop. Be alert in the mountains for rockslides and rocks in the road.
Updated: Jan 1, 12:34 PM Source: NWS Alert