Rock Falls (IL) Temperature by Month
The average annual maximum temperature in Rock Falls, Illinois, United States of America is 15°C (59°F), with daytime highs ranging from -1°C (30°F) in January to 29°C (84°F) in July. This page covers monthly averages, day-night differences, and how Rock Falls compares to cities worldwide.
Rock Falls Monthly Temperatures
Visitors to Rock Falls can expect significant temperature changes throughout the year. Nighttime temperatures also vary widely, ranging from 17°C (63°F) in July to -11°C (12°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in Rock Falls by month:
Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM.
The chart below shows the average temperature throughout the year:
Temperature: Rock Falls vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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Rock Falls vs World: Temperature Compared
Rock Falls's average annual maximum temperature is 15°C (59°F). To put that in context, here's how it compares to a few well-known destinations:
Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.
Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.
Chicago, USA averages 15°C (59°F) annually — known for extreme seasonal swings, from bitterly cold winters to warm summers.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Rock Falls this rarely lasts long on the ground.
For more on Rock Falls's weather — including monthly rainfall, sunshine hours, and humidity — visit our Rock Falls climate page.
