Ontario weather in October: Ontario, California: normal highs, lows, rain and records for October
Ontario in October has a normal high of 83°F and a normal low of 57°F, a daily mean of 70°F, falling from 86°F on the 1st to 80°F by the 31st. Measurable precipitation falls on 2 days in a normal October, 0.41 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 28°C and low of 14°C, 10 mm of precipitation in October.
- 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 October?
The normal high is 83°F and the normal low 57°F, for a daily mean of 69.8°F. October is 7.8°F cooler than September and 7.9°F warmer than November. October is the 5th warmest month of the year in Ontario and the 7th wettest. Across the month the normal high falls 6°F, from 86°F on October 1 to 80°F on October 31. From one year to the next October's mean temperature typically moves about 2.6°F either way (NOAA's standard deviation), so roughly two Octobers in three average between 67°F and 72°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 9%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| October 1 | 86°F | 61°F | 4% | 2% |
| October 8 | 84°F | 59°F | 5% | 2% |
| October 15 | 83°F | 57°F | 7% | 3% |
| October 22 | 81°F | 56°F | 8% | 3% |
| October 31 | 80°F | 53°F | 9% | 4% |
Every day of October: normal high, low and chance of precipitation (warmest afternoon October 1, coldest night October 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| October 1 | 86°F | 61°F | 4% | 2% | 11 h 50 min |
| October 2 | 86°F | 61°F | 4% | 2% | 11 h 50 min |
| October 3 | 86°F | 60°F | 4% | 2% | 11 h 50 min |
| October 4 | 85°F | 60°F | 4% | 2% | 11 h 50 min |
| October 5 | 85°F | 60°F | 4% | 2% | 11 h 40 min |
| October 6 | 85°F | 60°F | 5% | 2% | 11 h 40 min |
| October 7 | 85°F | 59°F | 5% | 2% | 11 h 40 min |
| October 8 | 84°F | 59°F | 5% | 2% | 11 h 40 min |
| October 9 | 84°F | 59°F | 5% | 2% | 11 h 40 min |
| October 10 | 84°F | 59°F | 6% | 2% | 11 h 30 min |
| October 11 | 84°F | 58°F | 6% | 2% | 11 h 30 min |
| October 12 | 83°F | 58°F | 6% | 3% | 11 h 30 min |
| October 13 | 83°F | 58°F | 6% | 3% | 11 h 30 min |
| October 14 | 83°F | 58°F | 7% | 3% | 11 h 30 min |
| October 15 | 83°F | 57°F | 7% | 3% | 11 h 20 min |
| October 16 | 82°F | 57°F | 7% | 3% | 11 h 20 min |
| October 17 | 82°F | 57°F | 7% | 3% | 11 h 20 min |
| October 18 | 82°F | 57°F | 7% | 3% | 11 h 20 min |
| October 19 | 82°F | 56°F | 8% | 3% | 11 h 20 min |
| October 20 | 82°F | 56°F | 8% | 3% | 11 h 10 min |
| October 21 | 81°F | 56°F | 8% | 3% | 11 h 10 min |
| October 22 | 81°F | 56°F | 8% | 3% | 11 h 10 min |
| October 23 | 81°F | 55°F | 8% | 3% | 11 h 10 min |
| October 24 | 81°F | 55°F | 8% | 4% | 11 h 10 min |
| October 25 | 81°F | 55°F | 9% | 4% | 11 h |
| October 26 | 81°F | 55°F | 9% | 4% | 11 h |
| October 27 | 80°F | 54°F | 9% | 4% | 11 h |
| October 28 | 80°F | 54°F | 9% | 4% | 11 h |
| October 29 | 80°F | 54°F | 9% | 4% | 11 h |
| October 30 | 80°F | 54°F | 9% | 4% | 10 h 50 min |
| October 31 | 80°F | 53°F | 9% | 4% | 10 h 50 min |
- Normal high
- 83°FOctober average
- Normal low
- 57°FOctober average
- Precipitation
- 0.41 inmonth total
- Days with precipitation
- 20.01 inch or more
- Days at 90°F or more
- 8
- Daylight
- 11 h 50 min to 10 h 50 minOctober 1 to October 31
- Days at 70°F or more
- 27
- Days at 80°F or more
- 18
- Sunshine
- 93%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 October?
On a given October day the chance of 0.01 inch or more is 7% on average, highest around October 31 (9%). In all, 0.41 in falls on 2 days of a normal October.
In a normal October in Ontario, 8 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003102.
What are the records for October in Ontario?
The warmest October temperature on this station's record (since 1998) is 107°F, on October 1, 2012; the coldest is 41°F, on October 31, 2019. The wettest October brought 3.59 in (2004).
The October mean against the 1991-2020 normal of 69.8°F: 2021 69.3°F (−0.5), 2022 70.4°F (+0.6), 2023 71.7°F (+1.9), 2024 73.0°F (+3.2), 2025 69.2°F (−0.6). 3 of 5 ran warmer than normal.
| October | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 69.3°F | −0.5°F | 0.26 in |
| 2022 | 70.4°F | +0.6°F | 0.30 in |
| 2023 | 71.7°F | +1.9°F | 0.00 in |
| 2024 | 73.0°F | +3.2°F | 0.06 in |
| 2025 | 69.2°F | −0.6°F | 1.08 in |
Source: records: ACIS, station USW00003102; recent months: ACIS, station USW00003102. Records and recent months use complete months only.
How does October in Ontario compare across California?
Across the 219 places PlainClimate covers in California, October normal highs run from 58°F in Tahoma to 93°F in Brawley; Ontario's is 83°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.