Romeoville weather in October: Romeoville, Illinois: normal highs, lows, rain and records for October
Romeoville in October has a normal high of 64°F and a normal low of 44°F, a daily mean of 54°F, falling from 71°F on the 1st to 57°F by the 31st. Measurable precipitation falls on 11 days in a normal October, 3.67 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 18°C and low of 6°C, 93 mm of precipitation and 0 cm of snow in October.
- NOAA stationRomeoville Weather Office
- Station IDUSC00117457
- Location41.60°N 88.08°W
- Elevation660 ft (201 m)
- From the center2 miles
- Population41,177
- Jan 32° 16°
- Feb 36° 20°
- Mar 49° 30°
- Apr 61° 40°
- May 72° 50°
- Jun 82° 60°
- Jul 85° 65°
- Aug 83° 63°
- Sep 76° 55°
- Oct 64° 44°
- Nov 49° 32°
- Dec 37° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Romeoville in October?
The normal high is 64°F and the normal low 44°F, for a daily mean of 53.7°F. October is 12.2°F cooler than September and 13.3°F warmer than November. October is the 6th warmest month of the year in Romeoville and the 6th wettest. Across the month the normal high falls 14°F, from 71°F on October 1 to 57°F on October 31. From one year to the next October's mean temperature typically moves about 2.5°F either way (NOAA's standard deviation), so roughly two Octobers in three average between 51°F and 56°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 33%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| October 1 | 71°F | 49°F | 32% | 19% |
| October 8 | 68°F | 47°F | 32% | 19% |
| October 15 | 64°F | 44°F | 33% | 20% |
| October 22 | 61°F | 41°F | 33% | 19% |
| October 31 | 57°F | 38°F | 32% | 18% |
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 | 71°F | 49°F | 32% | 19% | 11 h 50 min |
| October 2 | 70°F | 49°F | 32% | 19% | 11 h 50 min |
| October 3 | 70°F | 49°F | 32% | 20% | 11 h 40 min |
| October 4 | 69°F | 48°F | 32% | 20% | 11 h 40 min |
| October 5 | 69°F | 48°F | 32% | 20% | 11 h 40 min |
| October 6 | 69°F | 47°F | 32% | 20% | 11 h 30 min |
| October 7 | 68°F | 47°F | 32% | 19% | 11 h 30 min |
| October 8 | 68°F | 47°F | 32% | 19% | 11 h 30 min |
| October 9 | 67°F | 46°F | 32% | 20% | 11 h 30 min |
| October 10 | 67°F | 46°F | 33% | 20% | 11 h 20 min |
| October 11 | 66°F | 45°F | 33% | 20% | 11 h 20 min |
| October 12 | 66°F | 45°F | 33% | 20% | 11 h 20 min |
| October 13 | 65°F | 45°F | 33% | 20% | 11 h 20 min |
| October 14 | 65°F | 44°F | 33% | 20% | 11 h 10 min |
| October 15 | 64°F | 44°F | 33% | 20% | 11 h 10 min |
| October 16 | 64°F | 44°F | 33% | 20% | 11 h 10 min |
| October 17 | 63°F | 43°F | 33% | 20% | 11 h |
| October 18 | 63°F | 43°F | 33% | 19% | 11 h |
| October 19 | 62°F | 42°F | 33% | 19% | 11 h |
| October 20 | 62°F | 42°F | 33% | 19% | 11 h |
| October 21 | 62°F | 42°F | 33% | 19% | 10 h 50 min |
| October 22 | 61°F | 41°F | 33% | 19% | 10 h 50 min |
| October 23 | 61°F | 41°F | 33% | 19% | 10 h 50 min |
| October 24 | 60°F | 40°F | 33% | 19% | 10 h 50 min |
| October 25 | 60°F | 40°F | 33% | 19% | 10 h 40 min |
| October 26 | 59°F | 40°F | 33% | 19% | 10 h 40 min |
| October 27 | 59°F | 39°F | 32% | 18% | 10 h 40 min |
| October 28 | 58°F | 39°F | 32% | 18% | 10 h 40 min |
| October 29 | 58°F | 39°F | 32% | 18% | 10 h 30 min |
| October 30 | 57°F | 38°F | 32% | 18% | 10 h 30 min |
| October 31 | 57°F | 38°F | 32% | 18% | 10 h 30 min |
- Normal high
- 64°FOctober average
- Normal low
- 44°FOctober average
- Precipitation
- 3.67 inmonth total
- Days with precipitation
- 110.01 inch or more
- Snowfall
- 0.1 inmonth total
- Nights at 32°F or colder
- 3
- Daylight
- 11 h 50 min to 10 h 30 minOctober 1 to October 31
- Days at 70°F or more
- 9
- Days at 80°F or more
- 2
- Sunshine
- 71%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00117457; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Romeoville in October?
On a given October day the chance of 0.01 inch or more is 32% on average, highest around October 14 (33%). In all, 3.67 in falls on 11 days of a normal October, 1 of them with an inch or more.
In a normal October in Romeoville, 3 nights fall to freezing and snowfall averages 0.1 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00117457.
What are the records for October in Romeoville?
The warmest October temperature on this station's record (since 1992) is 89°F, on October 4, 2005; the coldest is 20°F, on October 19, 1992. The wettest October brought 8.37 in (2017); the snowiest, 2.1 inches (2019).
The October mean against the 1991-2020 normal of 53.7°F: 2021 59.0°F (+5.3), 2022 52.5°F (−1.2), 2023 54.0°F (+0.3), 2024 57.9°F (+4.2), 2025 56.8°F (+3.1). 4 of 5 ran warmer than normal.
| October | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 59.0°F | +5.3°F | 7.55 in |
| 2022 | 52.5°F | −1.2°F | 2.53 in |
| 2023 | 54.0°F | +0.3°F | 3.50 in |
| 2024 | 57.9°F | +4.2°F | 0.95 in |
| 2025 | 56.8°F | +3.1°F | 1.60 in |
Source: records: ACIS, station USC00117457; recent months: ACIS, station USC00117457. Records and recent months use complete months only.
How does October in Romeoville compare across Illinois?
Across the 144 places PlainClimate covers in Illinois, October normal highs run from 60°F in Barrington to 73°F in Anna; Romeoville's is 64°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.