Rochelle (IL) Temperature by Month

The average annual maximum temperature in Rochelle, Illinois, United States of America is 14°C (57°F), with daytime highs ranging from -2°C (28°F) in January to 28°C (82°F) in July. This page covers monthly averages, day-night differences, and how Rochelle compares to cities worldwide.

In Rochelle, temperatures differ significantly between summer and winter months. Nighttime lows reflect this range, dropping from 16°C (61°F) in July to -11°C (12°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Rochelle by month:

Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM.

The chart below shows the average temperature throughout the year:

Rochelle's average annual maximum temperature is 14°C (57°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Reykjavík, Iceland averages 9°C (48°F) a year, mild summers by Icelandic standards, but cold winters and frequent wind.

Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

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.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Rochelle's weather, including monthly rainfall, sunshine hours, and humidity, visit our Rochelle climate page.