Rock Island (IL) monthly weather averages

Contents

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Rock Island

Rock Island average temperature chart (Celsius) Rock Island average temperature chart (Fahrenheit)
Average monthly temperatures in Rock Island (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C -2.3 1 7.8 16.2 23 28.2 29.9 28.7 24.6 18.3 9.1 0.8
°F 27.8 33.7 46 61.2 73.5 82.8 85.8 83.7 76.3 64.9 48.4 33.5

Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

Average rainfall & rainy days

The graph below shows the average rainfall and number of rainy days per month.

Rock Island monthly rainfall chart (mm) Rock Island monthly rainfall chart (inches)
Average monthly rainfall in Rock Island (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 35 26 63 90 94 106 114 99 96 66 57 48
inches 1.4 1 2.5 3.5 3.7 4.2 4.5 3.9 3.8 2.6 2.2 1.9
Rainy days 9 8 11 11 12 10 10 9 9 9 9 10

Average annual rainfall in Rock Island: 846mm (333.1 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Rock Island

Rock Island average daily sunshine chart
Average daily sunshine Rock Island
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 5.4 6.3 6.6 7.8 9.2 10.4 10.6 9.7 8.1 7 4.7 4.3

Day / night temperatures

The graph below shows the daily range of temperatures for each month.

Rock Island average minimum / maximum temperatures (Celsius) Rock Island average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Rock Island (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -11.7 -8.8 -2.5 4.1 10.5 15.7 18.2 16.8 12.3 6.2 -0.6 -7.9
Max °C -2.1 1.2 8.1 16.5 23.4 28.5 30.2 29 24.9 18.6 9.4 1.1
Min °F 10.9 16.2 27.6 39.4 50.8 60.3 64.8 62.2 54.1 43.2 31 17.9
Max °F 19.6 25.2 37 50.5 62.4 71.8 75.6 73.2 65.5 54.3 39.9 25.9

Sea temperature

The graph below shows the average sea temperature.

Rock Island average sea temperature chart (Celsius) Rock Island average sea temperature chart (Fahrenheit)
Average sea temperature around Rock Island in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 7.7 7.3 7.6 8.6 10.4 12.8 16.5 20.2 18.8 14.4 11.1 9
°F 45.9 45.2 45.7 47.5 50.7 55.1 61.7 68.4 65.8 57.9 52 48.2

Wind speed

The graph below shows the average wind speed.

Rock Island average winspeed by month (km/h) Rock Island average winspeed by month (mph)
Average wind speed in Rock Island (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 19 18 21 21 17 16 14 13 14 17 18 18
mph 12 11 13 13 11 10 9 8 9 10 11 11

A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

Relative humidity

The graph below shows the average relative humidity.

Rock Island relative humidity averages
Average relative humidity in Rock Island
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
71% 71% 69% 64% 65% 66% 71% 73% 73% 69% 72% 75%

Other monthly averages

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Beta

Current (hourly) weather 15 day forecast

Rock Island weather stats

Rock Island weather statistics
Hottest month: July 29.9°C 85.8°F
Driest month: February 26mm 1ins
Sunniest month: July 10.6hrs
Coldest month: January -2.3°C 27.9°F
Wettest month: July 114mm 4.5ins
Warmest sea: August 20.2°C 68.4°F
Map showing location of Rock Island (41.50948, -90.57875) Rock Island map pin © Google

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