With a population of around 10,200, Waterloo sits in Illinois, United States. The city operates in the Central Time Zone.
Expect a humid continental climate in Waterloo: average highs of 89°F in midsummer, lows near 24°F in midwinter, and an annual mean of 57°F. Precipitation totals roughly 41 inches per year, concentrated around May, with February typically the driest month.
View historical weather for Waterloo · More cities in Illinois