With a population of around 5,000, Fairfield sits in Illinois, United States. The city operates in the Central Time Zone.
Recent weather here gives a sense of typical conditions: in 2025, Fairfield recorded a mean annual temperature of 56°F, ranging from -6°F lows in January to 92°F highs in July, with about 44 inches of precipitation across the year.
View historical weather for Fairfield · More cities in Illinois