Annual mean 11°C · wettest around May · prevailing wind SW
Warmest
27.8 °C
Coldest
-2.8 °C
Wettest
64%
Windiest
5.7 m/s
Prevailing
SW
4.6 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Romeoville over the whole year is 11°C. July is the hottest month, with highs of about 27°C; January is the coldest, with lows of about -5°C. Romeoville has no sharply defined rainy season: the chance of rain on a given day runs from 47% in January, the driest month, to 53% in May, the wettest. Winds in Romeoville are highest in March, averaging 4.4 m/s (16 km/h), and lightest in August, at 2.6 m/s (9 km/h). The prevailing wind is from the SW. The clearest skies in Romeoville come in August, when the sky is typically 39% covered; January is the cloudiest month, at 64%.
Month by month Romeoville climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
-2°C
-5°C
-8°C
47%
64%
4.2 m/s
0
0
2
February
1°C
-3°C
-5°C
48%
53%
4.2 m/s
1
0
9
March
7°C
2°C
2°C
53%
55%
4.4 m/s
4
0
22
April
13°C
6°C
8°C
49%
53%
4.4 m/s
20
1
46
May
20°C
13°C
17°C
53%
50%
3.8 m/s
50
15
58
June
26°C
19°C
25°C
51%
41%
3.4 m/s
55
41
34
July
27°C
21°C
28°C
51%
40%
2.7 m/s
44
57
15
August
27°C
19°C
27°C
51%
39%
2.6 m/s
50
53
20
September
24°C
16°C
23°C
51%
39%
2.9 m/s
64
34
45
October
16°C
9°C
12°C
52%
48%
3.5 m/s
36
5
59
November
8°C
3°C
3°C
49%
51%
3.9 m/s
7
0
27
December
2°C
-2°C
-4°C
51%
59%
4.0 m/s
0
0
7
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Romeoville weather by season
Year round, Romeoville has days of about -2°C at their warmest in January, its coolest month, and 27°C in July, its warmest; the coolest hours of the day run from -5°C to 21°C through the year, and the average temperature over the year is 11°C around the clock. Rain is most likely around May and least likely around January. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Romeoville weather in winterDecember to February
High 0°CLow -3°CRain 48%
Winter in Romeoville has typical daily highs of about 0°C and lows of about -3°C, with a 48% chance of rain on a given day.
Romeoville weather in springMarch to May
High 13°CLow 7°CRain 51%
Spring in Romeoville has typical daily highs of about 13°C and lows of about 7°C, with a 51% chance of rain on a given day.
Romeoville weather in summerJune to August
High 27°CLow 20°CRain 51%
Summer in Romeoville has typical daily highs of about 27°C and lows of about 20°C, with a 51% chance of rain on a given day.
Romeoville weather in autumnSeptember to November
High 16°CLow 9°CRain 51%
Autumn in Romeoville has typical daily highs of about 16°C and lows of about 9°C, with a 51% chance of rain on a given day.
When is the rainy season in Romeoville?
Romeoville has no sharply defined rainy season: the chance of rain on a given day runs from 47% in January, the driest month, to 53% in May, the wettest.
What time of year is Romeoville windiest?
Winds in Romeoville are highest in March, averaging 4.4 m/s (16 km/h), and lightest in August, at 2.6 m/s (9 km/h). The prevailing wind is from the SW.
What is the average temperature in Romeoville year round?
The average temperature in Romeoville over the whole year is 11°C. July is the hottest month, with highs of about 27°C; January is the coldest, with lows of about -5°C.