Randolph County, IL Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in Randolph County, IL

Coverage rankings for Randolph County, IL

AT&T currently ranks first for coverage in this area, with a coverage score of 81.6. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.

RankCarrierScoreOverall4G LTE5GFast 5GAverage Signal
1AT&T81.697.1%97.1%79.2%59.6% -114 dBm
2T-Mobile69.574.6%74.3%62.5%41.2% -95 dBm
3Verizon62.597.4%97.4%20.7%10.5% -97 dBm

Scores include coverage area, network type, and average signal strength.

Cell phone coverage map for Randolph County, IL

Zoom in for local detail. Tap or click a colored area to see coverage and signal details. On mobile, use two fingers to move the map.

Coverage Key
Less covered More covered
Darker areas mean the carrier covers more of that location.

Map data © OpenStreetMap contributors, © CARTO. Rendered with MapLibre. FCC BDC mobile coverage processed by Compare Wireless Carriers.

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Cell phone coverage by network in Randolph County, IL

#1

AT&T

Coverage Score 81.6
In Randolph County, IL
Overall
97.1%
4G LTE
97.1%
5G
79.2%
Fast 5G
59.6%
Average Signal -114 dBm
#2

T-Mobile

Coverage Score 69.5
In Randolph County, IL
Overall
74.6%
4G LTE
74.3%
5G
62.5%
Fast 5G
41.2%
Average Signal -95 dBm
#3

Verizon

Coverage Score 62.5
In Randolph County, IL
Overall
97.4%
4G LTE
97.4%
5G
20.7%
Fast 5G
10.5%
Average Signal -97 dBm
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Coverage by city in Randolph County, IL

Cities and towns are shown for county-level comparison. Coverage percentages use land-area only coverage.

CityVerizonAT&TT-Mobile
Baldwin, IL 100.0% 100.0% 46.7% 0.0% -83 dBm 100.0% 100.0% 100.0% 100.0% -89 dBm 100.0% 100.0% 100.0% 100.0% -63 dBm
Chester, IL 100.0% 100.0% 59.9% 45.6% -90 dBm 99.3% 99.3% 90.5% 81.0% -107 dBm 98.6% 98.6% 93.9% 71.4% -90 dBm
Coulterville, IL 100.0% 100.0% 0.0% 0.0% -72 dBm 100.0% 100.0% 100.0% 100.0% -114 dBm 46.2% 46.2% 7.7% 7.7% -107 dBm
Ellis Grove, IL 100.0% 100.0% 0.0% 0.0% -99 dBm 91.7% 91.7% 83.3% 25.0% -118 dBm 75.0% 75.0% 66.7% 41.7% -96 dBm
Evansville, IL 100.0% 100.0% 0.0% 0.0% -80 dBm 100.0% 100.0% 100.0% 70.0% -97 dBm 100.0% 100.0% 95.0% 70.0% -93 dBm
Kaskaskia, IL 100.0% 100.0% 100.0% 0.0% -100 dBm 100.0% 100.0% 100.0% 100.0% -120 dBm 100.0% 100.0% 100.0% 100.0% -90 dBm
Percy, IL 100.0% 100.0% 48.0% 40.0% -93 dBm 100.0% 100.0% 100.0% 96.0% -108 dBm 100.0% 100.0% 100.0% 100.0% -85 dBm
Prairie Du Rocher, IL 100.0% 100.0% 0.0% 0.0% -105 dBm 100.0% 100.0% 100.0% 30.8% -119 dBm 84.6% 84.6% 84.6% 30.8% -98 dBm
Red Bud, IL 100.0% 100.0% 16.1% 0.0% -79 dBm 100.0% 100.0% 100.0% 85.5% -103 dBm 100.0% 100.0% 100.0% 100.0% -75 dBm
Rockwood, IL 100.0% 100.0% 0.0% 0.0% -97 dBm 100.0% 100.0% 66.7% 66.7% -113 dBm 66.7% 66.7% 33.3% 0.0% -100 dBm
Ruma, IL 100.0% 100.0% 0.0% 0.0% -94 dBm 100.0% 100.0% 100.0% 77.8% -113 dBm 94.4% 94.4% 88.9% 38.9% -98 dBm
Sparta, IL 100.0% 100.0% 86.4% 71.7% -90 dBm 100.0% 100.0% 100.0% 90.7% -105 dBm 97.1% 97.1% 93.2% 77.1% -88 dBm
Steeleville, IL 100.0% 100.0% 94.1% 94.1% -80 dBm 100.0% 100.0% 100.0% 94.1% -93 dBm 100.0% 100.0% 100.0% 100.0% -75 dBm
Tilden, IL 100.0% 100.0% 40.0% 24.0% -96 dBm 100.0% 100.0% 100.0% 80.0% -112 dBm 48.0% 48.0% 16.0% 8.0% -105 dBm
Willisville, IL 100.0% 100.0% 0.0% 0.0% -74 dBm 100.0% 100.0% 72.7% 63.6% -119 dBm 90.9% 90.9% 54.5% 0.0% -104 dBm

About The Coverage Data

Coverage and signal estimates are derived by Compare Wireless Carriers from carrier-reported data in the FCC’s National Broadband Coverage Map, last updated in June 2025. “Percent covered” shows how much of the city or ZIP code area has a carrier signal, whether weak or strong. Signal bars show the estimated average signal strength in areas of Randolph County, IL where that carrier has coverage.

If a carrier says you should have service but you do not, run a challenge test with the FCC Mobile Speed Test App. The FCC uses those results to check carrier-submitted coverage data and requires a carrier response when enough tests show a pattern of inaccurate coverage reporting.