Galena (IL) Temperature by Month
The average annual maximum temperature in Galena, 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 Galena compares to cities worldwide.
Galena Monthly Temperatures
Visitors to Galena can expect significant temperature changes throughout the year. Nighttime temperatures also vary widely, ranging from 17°C (63°F) in July to -12°C (10°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in Galena by month:
The coolest part of the day is typically between 4 AM and 6 AM, while 3 PM is usually the warmest, when solar heating is at its peak. July, the city's warmest month, averages 301 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in July
Historical Galena Temperatures: 1976-2026
Browse day-by-day temperature records for Galena spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: Galena 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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Galena vs World: Temperature Compared
Galena'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:
Seville, Spain averages 23°C (73°F) a year — one of the warmer cities in Western Europe, with long hot summers.
Reykjavík, Iceland averages 9°C (48°F) a year — mild summers by Icelandic standards, but cold winters and frequent wind.
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.
Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.
Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.
For more on Galena's weather — including monthly rainfall, sunshine hours, and humidity — visit our Galena climate page.
