Editing Randolph County, Illinois (section)

==Geography==
According to the [[U.S. Census Bureau]], the county has a total area of {{convert|597|sqmi}}, of which {{convert|576|sqmi}} is land and {{convert|22|sqmi}} (3.6%) is water.<ref name="census-density"/>

The [[Kaskaskia River]] flows into the [[Mississippi River]] in Randolph County. At this point the Mississippi, which usually defines the border between Illinois and [[Missouri]], is entirely in Illinois. The Mississippi changed its course in the late-nineteenth century, leaving Kaskaskia, the former state capital, on the west side of the river. The boundary of the State, however, follows the old course of the river, leaving Illinois with an exclave on the western shore of the Mississippi River. A smaller enclave, Crains Island, is a few miles further down the river.

===Climate and weather===
{{climate chart
|[[Chester, Illinois]]
|22|39|1.85
|26|46|1.99
|35|56|3.51
|45|68|3.42
|54|78|4.30
|64|87|3.85
|68|91|3.76
|66|89|3.39
|58|82|3.19
|46|71|3.08
|36|56|4.16
|27|44|3.16
|float=right
|units=imperial
|clear=both
|source=The Weather Channel<ref name="weather">{{cite web
  |url=http://www.weather.com/weather/wxclimatology/monthly/graph/USIL0221
  |title=Monthly Averages for Chester, Illinois
  |access-date=January 27, 2011
  |publisher=The Weather Channel
}}</ref>}}
In recent years, average temperatures in the county seat of Chester have ranged from a low of {{convert|22|°F}} in January to a high of {{convert|91|°F}} in July, although a record low of {{convert|-18|°F}} was recorded in January 1985 and a record high of {{convert|113|°F}} was recorded in July 2012. Average monthly precipitation ranged from {{convert|1.85|in}} in January to {{convert|4.30|in}} in May.<ref name="weather"/>

===Major highways===
{{div col}}
* [[Image:Illinois 3.svg|20px]] [[Illinois Route 3]]
* [[Image:Illinois 4.svg|20px]] [[Illinois Route 4]]
* [[Image:Illinois 13.svg|20px]] [[Illinois Route 13]]
* [[Image:Illinois 150.svg|20px]] [[Illinois Route 150]]
* [[Image:Illinois 153.svg|20px]] [[Illinois Route 153]]
* [[Image:Illinois 154.svg|20px]] [[Illinois Route 154]]
* [[Image:Illinois 155.svg|20px]] [[Illinois Route 155]]
* [[Image:Illinois 159.svg|20px]] [[Illinois Route 159]]
{{div col end}}

===Adjacent counties===
* [[Monroe County, Illinois|Monroe County]] (northwest)
* [[St. Clair County, Illinois|St. Clair County]] (north)
* [[Washington County, Illinois|Washington County]] (northeast)
* [[Perry County, Illinois|Perry County]] (east)
* [[Jackson County, Illinois|Jackson County]] (southeast)
* [[Perry County, Missouri|Perry County]], [[Missouri]] (south)
* [[Ste. Genevieve County, Missouri|Ste. Genevieve County]], [[Missouri]] (southwest)

Randolph County is among the few counties in the United States to border two counties with the same name (Perry County in Missouri and Illinois).