California · NWS SGX office

Rancho Cucamonga, CA weather

It is 57°F and clear at Ontario International Airport as of Oct 28, 5:00 AM PDT. Overnight: Partly Cloudy, low near 55°F. Forecast from the National Weather Service, issued Oct 28, 12:03 AM PDT.

Updated Oct 28, 5:16 AM PDT (snapshot)

Current conditions

Temperature

57°F

Clear

Wind

Calm

Humidity 88% · dew point 54°F

Pressure · visibility

29.96 inHg

Visibility 10 mi

Observed at Ontario International Airport (KONT), Oct 28, 5:00 AM PDT. Station readings can lag or be missing.

Alerts for this area

No active NWS alerts cover the Rancho Cucamonga forecast zone right now.

Around the NWS SGX forecast area

1 active alert covers zones served by the SGX office near Rancho Cucamonga:

  • Coastal Flood Warning

From the alert snapshot of Oct 28, 2026, 8:14 AM EDT. California has 8 active alerts: see them all.

For official warnings, check weather.gov and your local authorities. OpenForecast repeats National Weather Service alerts and may be delayed or incomplete. Follow instructions from emergency officials.

Next 24 hours

Hourly forecast for Rancho Cucamonga (local time)
TimeTempForecastPrecip. chanceWind
Wed 5 AM56°FPartly Cloudy0% 0 mph
Wed 6 AM55°FMostly Sunny0% 0 mph
Wed 7 AM55°FMostly Sunny0% 0 mph
Wed 8 AM57°FMostly Sunny0% 0 mph
Wed 9 AM60°FMostly Sunny0% 0 mph
Wed 10 AM62°FMostly Sunny0% 0 mph
Wed 11 AM66°FSunny0% 0 mph
Wed 12 PM69°FSunny0% 0 mph
Wed 1 PM71°FSunny0% 0 mph
Wed 2 PM73°FSunny0%S 5 mph
Wed 3 PM74°FSunny0%SW 5 mph
Wed 4 PM74°FSunny0%SW 5 mph
Wed 5 PM73°FSunny0%SW 5 mph
Wed 6 PM70°FMostly Clear0%SW 5 mph
Wed 7 PM68°FMostly Clear0%W 5 mph
Wed 8 PM64°FPartly Cloudy0%W 5 mph
Wed 9 PM63°FPartly Cloudy0%W 5 mph
Wed 10 PM62°FPartly Cloudy0%W 5 mph
Wed 11 PM60°FMostly Cloudy0% 0 mph
Thu 12 AM60°FMostly Cloudy0% 0 mph
Thu 1 AM58°FMostly Cloudy0% 0 mph
Thu 2 AM58°FMostly Cloudy0% 0 mph
Thu 3 AM57°FMostly Cloudy0% 0 mph
Thu 4 AM57°FMostly Cloudy0% 0 mph

Hourly values come from the NWS gridded forecast for the 2.5 km grid square that covers the city's center point. Conditions elsewhere in Rancho Cucamonga can differ.

7-day forecast

Overnight

Low 55°F

Partly cloudy, with a low around 55. Northwest wind around 0 mph.

Wednesday

High 74°F·Low 56°F

Mostly sunny, with a high near 74. Southwest wind 0 to 5 mph.

Wednesday Night: Mostly cloudy, with a low around 56. Northwest wind 0 to 5 mph.

Thursday

High 73°F·Low 58°F

Partly sunny, with a high near 73. Southwest wind 0 to 5 mph.

Thursday Night: Mostly cloudy, with a low around 58. Southwest wind 0 to 5 mph.

Friday

High 69°F·Low 54°F

Partly sunny, with a high near 69.

Friday Night: Partly cloudy, with a low around 54.

Saturday

High 68°F·Low 56°F

A chance of rain showers after 11am. Mostly cloudy, with a high near 68.

Saturday Night: Rain showers likely. Cloudy, with a low around 56.

Sunday

High 67°F·Low 53°F

A chance of rain showers before 4pm. Partly sunny, with a high near 67.

Sunday Night: Mostly clear, with a low around 53.

Monday

High 72°F·Low 55°F

Sunny, with a high near 72.

Monday Night: Mostly clear, with a low around 55.

Tuesday

High 72°F

Sunny, with a high near 72.

Nearby cities

Larger cities in the area

Other cities in San Bernardino County

See every city we cover in California, or check all active alerts.

About this forecast

Forecast office
Rancho Cucamonga is served by the National Weather Service SGX forecast office, forecast zone CAZ048, county zone CAC071.
Location used
The Census Bureau's internal point for Rancho Cucamonga (34.1303, -117.5661), in San Bernardino County. Population: 176,675 (2024 estimate), number 28 of the 296 California cities on this site.
Radar
Nearest NWS radar: KSOX. View it on radar.weather.gov.

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Sources

  • Forecast, hourly forecast, observations and alerts: National Weather Service API, api.weather.gov/points/34.1303,-117.5661 (forecast issued Oct 28, 12:03 AM PDT).
  • Official forecast page: forecast.weather.gov.
  • City location and population: U.S. Census Bureau, Vintage 2024 population estimates and 2024 Gazetteer files.
  • Snapshot taken Oct 28, 2026. The NWS and Census Bureau do not endorse OpenForecast.

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