Annual mean 11°C · wettest around May · prevailing wind SW
Warmest
28.4 °C
Coldest
-3.3 °C
Wettest
28%
Windiest
6.3 m/s
Prevailing
SW
4.9 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 Rock Island over the whole year is 11°C. July is the hottest month, with highs of about 28°C; January is the coldest, with lows of about -6°C. Rock Island has no sharply defined rainy season: the chance of rain on a given day runs from 23% in January, the driest month, to 30% in May, the wettest. Winds in Rock Island are highest in April, averaging 4.8 m/s (17 km/h), and lightest in August, at 2.5 m/s (9 km/h). The prevailing wind is from the SW. The clearest skies in Rock Island come in June, when the sky is typically 25% covered; January is the cloudiest month, at 54%.
Month by month Rock Island 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
-6°C
-9°C
23%
54%
4.2 m/s
0
0
2
February
1°C
-4°C
-5°C
23%
42%
4.4 m/s
2
0
11
March
8°C
2°C
2°C
28%
47%
4.7 m/s
5
0
27
April
14°C
6°C
8°C
29%
43%
4.8 m/s
25
1
51
May
21°C
13°C
18°C
30%
41%
3.8 m/s
57
18
61
June
27°C
19°C
26°C
28%
25%
3.4 m/s
53
54
27
July
28°C
21°C
29°C
27%
27%
2.7 m/s
38
66
10
August
27°C
19°C
27°C
26%
27%
2.5 m/s
53
60
20
September
25°C
15°C
23°C
25%
27%
2.8 m/s
65
42
44
October
17°C
9°C
13°C
25%
37%
3.5 m/s
40
7
63
November
8°C
2°C
3°C
24%
40%
3.9 m/s
9
0
30
December
2°C
-2°C
-4°C
25%
49%
4.1 m/s
0
0
8
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 Rock Island weather by season
Year round, Rock Island has days of about -2°C at their warmest in January, its coolest month, and 28°C in July, its warmest; the coolest hours of the day run from -6°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.
Rock Island weather in winterDecember to February
High 0°CLow -4°CRain 23%
Winter in Rock Island has typical daily highs of about 0°C and lows of about -4°C, with a 23% chance of rain on a given day.
Rock Island weather in springMarch to May
High 14°CLow 7°CRain 29%
Spring in Rock Island has typical daily highs of about 14°C and lows of about 7°C, with a 29% chance of rain on a given day.
Rock Island weather in summerJune to August
High 27°CLow 20°CRain 27%
Summer in Rock Island has typical daily highs of about 27°C and lows of about 20°C, with a 27% chance of rain on a given day.
Rock Island weather in autumnSeptember to November
High 16°CLow 9°CRain 25%
Autumn in Rock Island has typical daily highs of about 16°C and lows of about 9°C, with a 25% chance of rain on a given day.
When is the rainy season in Rock Island?
Rock Island has no sharply defined rainy season: the chance of rain on a given day runs from 23% in January, the driest month, to 30% in May, the wettest.
What time of year is Rock Island windiest?
Winds in Rock Island are highest in April, averaging 4.8 m/s (17 km/h), and lightest in August, at 2.5 m/s (9 km/h). The prevailing wind is from the SW.
What is the average temperature in Rock Island year round?
The average temperature in Rock Island over the whole year is 11°C. July is the hottest month, with highs of about 28°C; January is the coldest, with lows of about -6°C.