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City of Ontario, CAOntario, CA 7-Day Night Weather Forecast
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Ontario, CA Weather Forecast
Ontario, CA Weather Forecast Date: 1134 AM PDT Sun Sep 20 2026
The area/counties/county of: San Bernardino And Riverside County Valleys, including the cities of: Riverside, San Bernardino, Ontario, Moreno Valley, Fontana, Rancho Cucamonga, and Corona.or toggle through each period.
Tonight... Partly cloudy this evening...Becoming mostly cloudy. Lows 56 to 62. Areas of winds west 10 mph this evening becoming light.
Monday... Mostly cloudy in the morning...Becoming mostly sunny. Highs 77 to 82. Light winds becoming southwest 10 to 15 mph in the afternoon.
Monday Night... Mostly clear in the evening...Becoming mostly cloudy. Lows 52 to 61. Areas of winds southwest to 10 mph in the evening becoming light.
Tuesday... Partly cloudy in the morning...Becoming sunny. Highs 81 to 86. Light winds becoming west 10 mph in the afternoon.
Tuesday Night... Clear. Lows 58 to 64. Areas of winds west to 10 mph in the evening becoming light.
Wednesday... Mostly sunny. Warmer. Highs 90 to 96.
Wednesday Night... Clear. Lows 62 to 68.
Thursday... Mostly sunny. Highs 92 to 97.
Thursday Night... Mostly clear. Lows 63 to 68.
Friday... Mostly sunny. Highs 90 to 95.
Friday Night... Mostly clear. Lows 60 to 66.
Saturday... Partly cloudy. Highs 88 to 93.
Saturday Night... Mostly clear in the evening...Becoming partly cloudy. Lows 59 to 66.
POP = Probability of Precipitation
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