Ontario weather in January: Ontario, California: normal highs, lows, rain and records for January
Ontario in January has a normal high of 68°F and a normal low of 45°F, a daily mean of 56°F, holding near 68°F all month. Measurable precipitation falls on 5 days in a normal January, 2.57 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 20°C and low of 7°C, 65 mm of precipitation in January.
- NOAA stationOntario International Airport
- Station IDUSW00003102
- Location34.06°N 117.60°W
- Elevation949 ft (289 m)
- From the center1 miles
- Population185,285
- Jan 68° 45°
- Feb 68° 46°
- Mar 72° 49°
- Apr 76° 51°
- May 80° 56°
- Jun 86° 60°
- Jul 94° 65°
- Aug 95° 65°
- Sep 91° 64°
- Oct 83° 57°
- Nov 75° 49°
- Dec 67° 44°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Ontario in January?
The normal high is 68°F and the normal low 45°F, for a daily mean of 56.1°F. January is 0.9°F warmer than December and 1.0°F cooler than February. January is the 11th warmest month of the year in Ontario and the 2nd wettest. Across the month the normal high rises 1°F, from 67°F on January 1 to 68°F on January 31. From one year to the next January's mean temperature typically moves about 2.4°F either way (NOAA's standard deviation), so roughly two Januarys in three average between 54°F and 59°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 19%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| January 1 | 67°F | 44°F | 17% | 11% |
| January 8 | 68°F | 44°F | 17% | 11% |
| January 15 | 68°F | 45°F | 16% | 11% |
| January 22 | 68°F | 45°F | 17% | 11% |
| January 31 | 68°F | 45°F | 19% | 13% |
Every day of January: normal high, low and chance of precipitation (warmest afternoon January 16, coldest night January 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| January 1 | 67°F | 44°F | 17% | 11% | 10 h |
| January 2 | 67°F | 44°F | 17% | 11% | 10 h |
| January 3 | 67°F | 44°F | 17% | 11% | 10 h |
| January 4 | 67°F | 44°F | 17% | 11% | 10 h |
| January 5 | 67°F | 44°F | 17% | 11% | 10 h |
| January 6 | 67°F | 44°F | 17% | 11% | 10 h |
| January 7 | 68°F | 44°F | 17% | 11% | 10 h |
| January 8 | 68°F | 44°F | 17% | 11% | 10 h |
| January 9 | 68°F | 44°F | 17% | 11% | 10 h |
| January 10 | 68°F | 44°F | 17% | 11% | 10 h |
| January 11 | 68°F | 45°F | 17% | 11% | 10 h |
| January 12 | 68°F | 45°F | 16% | 11% | 10 h |
| January 13 | 68°F | 45°F | 16% | 11% | 10 h |
| January 14 | 68°F | 45°F | 16% | 11% | 10 h 10 min |
| January 15 | 68°F | 45°F | 16% | 11% | 10 h 10 min |
| January 16 | 68°F | 45°F | 16% | 11% | 10 h 10 min |
| January 17 | 68°F | 45°F | 16% | 11% | 10 h 10 min |
| January 18 | 68°F | 45°F | 16% | 11% | 10 h 10 min |
| January 19 | 68°F | 45°F | 17% | 11% | 10 h 10 min |
| January 20 | 68°F | 45°F | 17% | 11% | 10 h 10 min |
| January 21 | 68°F | 45°F | 17% | 11% | 10 h 10 min |
| January 22 | 68°F | 45°F | 17% | 11% | 10 h 20 min |
| January 23 | 68°F | 45°F | 17% | 12% | 10 h 20 min |
| January 24 | 68°F | 45°F | 17% | 12% | 10 h 20 min |
| January 25 | 68°F | 45°F | 17% | 12% | 10 h 20 min |
| January 26 | 68°F | 45°F | 18% | 12% | 10 h 20 min |
| January 27 | 68°F | 45°F | 18% | 12% | 10 h 20 min |
| January 28 | 68°F | 45°F | 18% | 12% | 10 h 20 min |
| January 29 | 68°F | 45°F | 18% | 12% | 10 h 30 min |
| January 30 | 68°F | 45°F | 18% | 13% | 10 h 30 min |
| January 31 | 68°F | 45°F | 19% | 13% | 10 h 30 min |
- Normal high
- 68°FJanuary average
- Normal low
- 45°FJanuary average
- Precipitation
- 2.57 inmonth total
- Days with precipitation
- 50.01 inch or more
- Nights at 32°F or colder
- 1
- Daylight
- 10 h to 10 h 30 minJanuary 1 to January 31
- Days at 70°F or more
- 13
- Days at 80°F or more
- 3
- Sunshine
- 85%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003102; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Ontario in January?
On a given January day the chance of 0.01 inch or more is 17% on average, highest around January 31 (19%). In all, 2.57 in falls on 5 days of a normal January, 1 of them with an inch or more.
In a normal January in Ontario, 1 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003102.
What are the records for January in Ontario?
The warmest January temperature on this station's record (since 1998) is 90°F, on January 31, 2003; the coldest is 25°F, on January 14, 2007. The wettest January brought 8.15 in (2005).
The January mean against the 1991-2020 normal of 56.1°F: 2021 56.3°F (+0.2), 2022 56.3°F (+0.2), 2023 51.4°F (−4.7), 2024 54.9°F (−1.3), 2025 56.1°F (at normal), 2026 59.3°F (+3.2). 3 of 6 ran warmer than normal.
| January | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 56.3°F | +0.2°F | 2.61 in |
| 2022 | 56.3°F | +0.2°F | 0.02 in |
| 2023 | 51.4°F | −4.7°F | 6.08 in |
| 2024 | 54.9°F | −1.3°F | 0.78 in |
| 2025 | 56.1°F | at normal | 0.69 in |
| 2026 | 59.3°F | +3.2°F | 1.02 in |
Source: records: ACIS, station USW00003102; recent months: ACIS, station USW00003102. Records and recent months use complete months only.
How does January in Ontario compare across California?
Across the 219 places PlainClimate covers in California, January normal highs run from 37°F in Tahoma to 72°F in Brawley; Ontario's is 68°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.