Romeoville weather in July: Romeoville, Illinois: normal highs, lows, rain and records for July
Romeoville in July has a normal high of 85°F and a normal low of 65°F, a daily mean of 75°F, holding near 85°F all month. Measurable precipitation falls on 10 days in a normal July, 4.50 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 29°C and low of 18°C, 114 mm of precipitation in July.
- 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 July?
The normal high is 85°F and the normal low 65°F, for a daily mean of 74.6°F. July is 3.7°F warmer than June and 1.8°F warmer than August. July is the warmest month of the year in Romeoville and the 3rd wettest. From one year to the next July's mean temperature typically moves about 2.8°F either way (NOAA's standard deviation), so roughly two Julys in three average between 72°F and 77°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 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| July 1 | 84°F | 64°F | 35% | 23% |
| July 8 | 85°F | 64°F | 34% | 23% |
| July 15 | 85°F | 65°F | 32% | 22% |
| July 22 | 85°F | 65°F | 32% | 22% |
| July 31 | 84°F | 64°F | 32% | 22% |
Every day of July: normal high, low and chance of precipitation (warmest afternoon July 13, coldest night July 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| July 1 | 84°F | 64°F | 35% | 23% | 15 h 10 min |
| July 2 | 85°F | 64°F | 35% | 23% | 15 h 10 min |
| July 3 | 85°F | 64°F | 35% | 23% | 15 h 10 min |
| July 4 | 85°F | 64°F | 34% | 23% | 15 h 10 min |
| July 5 | 85°F | 64°F | 34% | 23% | 15 h 10 min |
| July 6 | 85°F | 64°F | 34% | 23% | 15 h 10 min |
| July 7 | 85°F | 64°F | 34% | 23% | 15 h |
| July 8 | 85°F | 64°F | 34% | 23% | 15 h |
| July 9 | 85°F | 65°F | 33% | 23% | 15 h |
| July 10 | 85°F | 65°F | 33% | 23% | 15 h |
| July 11 | 85°F | 65°F | 33% | 22% | 15 h |
| July 12 | 85°F | 65°F | 33% | 22% | 15 h |
| July 13 | 85°F | 65°F | 33% | 22% | 15 h |
| July 14 | 85°F | 65°F | 33% | 22% | 15 h |
| July 15 | 85°F | 65°F | 32% | 22% | 15 h |
| July 16 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 17 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 18 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 19 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 20 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 21 | 85°F | 65°F | 32% | 22% | 14 h 50 min |
| July 22 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 23 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 24 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 25 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 26 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 27 | 85°F | 65°F | 32% | 22% | 14 h 40 min |
| July 28 | 84°F | 65°F | 32% | 22% | 14 h 30 min |
| July 29 | 84°F | 65°F | 32% | 22% | 14 h 30 min |
| July 30 | 84°F | 65°F | 32% | 22% | 14 h 30 min |
| July 31 | 84°F | 64°F | 32% | 22% | 14 h 30 min |
- Normal high
- 85°FJuly average
- Normal low
- 65°FJuly average
- Precipitation
- 4.50 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 6
- Daylight
- 15 h 10 min to 14 h 30 minJuly 1 to July 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 25
- Sunshine
- 81%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 in Romeoville in July?
On a given July day the chance of 0.01 inch or more is 33% on average, highest around July 1 (35%). In all, 4.50 in falls on 10 days of a normal July, 1 of them with an inch or more.
In a normal July in Romeoville, 6 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00117457.
What are the records for July in Romeoville?
The warmest July temperature on this station's record (since 1992) is 102°F, on July 24, 2005; the coldest is 48°F, on July 2, 2001. The wettest July brought 12.91 in (1996).
The July mean against the 1991-2020 normal of 74.6°F: 2021 73.5°F (−1.0), 2022 73.9°F (−0.7), 2023 73.4°F (−1.2), 2024 74.0°F (−0.6), 2025 76.4°F (+1.8), 2026 75.7°F (+1.1). 2 of 6 ran warmer than normal.
| July | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 73.5°F | −1.0°F | 2.55 in |
| 2022 | 73.9°F | −0.7°F | 4.36 in |
| 2023 | 73.4°F | −1.2°F | 8.00 in |
| 2024 | 74.0°F | −0.6°F | 4.01 in |
| 2025 | 76.4°F | +1.8°F | 4.86 in |
| 2026 | 75.7°F | +1.1°F | 4.60 in |
Source: records: ACIS, station USC00117457; recent months: ACIS, station USC00117457. Records and recent months use complete months only.
How does July in Romeoville compare across Illinois?
Across the 144 places PlainClimate covers in Illinois, July normal highs run from 81°F in Barrington to 90°F in Belleville; Romeoville's is 85°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.