Coverage rankings for St. Clair County, IL
T-Mobile currently ranks first for coverage in this area, with a coverage score of 90.7. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.
| Rank | Carrier | Score | Overall | 4G LTE | 5G | Fast 5G | Average Signal |
|---|---|---|---|---|---|---|---|
| 1 | T-Mobile | 90.7 | 93.0% | 93.0% | 88.8% | 76.0% | -87 dBm |
| 2 | Verizon | 90.1 | 98.9% | 98.9% | 83.9% | 68.8% | -94 dBm |
| 3 | AT&T | 86.1 | 99.0% | 98.5% | 94.2% | 62.1% | -108 dBm |
Scores include coverage area, network type, and average signal strength.
Cell phone coverage map for St. Clair 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.
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 St. Clair County, IL
T-Mobile
- Overall
- 93.0%
- 4G LTE
- 93.0%
- 5G
- 88.8%
- Fast 5G
- 76.0%
Verizon
- Overall
- 98.9%
- 4G LTE
- 98.9%
- 5G
- 83.9%
- Fast 5G
- 68.8%
AT&T
- Overall
- 99.0%
- 4G LTE
- 98.5%
- 5G
- 94.2%
- Fast 5G
- 62.1%
Coverage varies by neighborhood. Your carrier shouldn’t.
US Mobile lets you switch between all three major networks, so you can choose the one that works best where you actually use your phone.
Pricing, network access, switching terms, and home internet availability may vary.
Coverage by city in St. Clair County, IL
Cities and towns are shown for county-level comparison. Coverage percentages use land-area only coverage.
| City | Verizon | AT&T | T-Mobile |
|---|---|---|---|
| Belleville, IL | 100.0% 100.0% 100.0% 94.0% -87 dBm | 99.3% 99.3% 98.1% 69.1% -102 dBm | 100.0% 100.0% 99.7% 96.0% -82 dBm |
| Brooklyn, IL | 100.0% 100.0% 100.0% 100.0% -90 dBm | 100.0% 100.0% 90.0% 45.0% -102 dBm | 100.0% 100.0% 100.0% 100.0% -69 dBm |
| Cahokia Heights, IL | 100.0% 100.0% 92.1% 78.5% -93 dBm | 100.0% 99.7% 99.7% 82.6% -101 dBm | 100.0% 100.0% 99.5% 93.8% -84 dBm |
| Caseyville, IL | 100.0% 100.0% 77.7% 73.7% -84 dBm | 100.0% 100.0% 98.3% 63.7% -103 dBm | 100.0% 100.0% 98.3% 95.0% -79 dBm |
| Darmstadt, IL | 100.0% 100.0% 100.0% 0.0% -90 dBm | 100.0% 100.0% 100.0% 100.0% -120 dBm | 100.0% 100.0% 0.0% 0.0% -110 dBm |
| Dupo, IL | 100.0% 100.0% 98.7% 93.7% -88 dBm | 99.4% 99.4% 91.2% 66.0% -116 dBm | 98.1% 98.1% 89.9% 66.7% -92 dBm |
| East Carondelet, IL | 100.0% 100.0% 96.3% 88.9% -98 dBm | 100.0% 100.0% 100.0% 74.1% -112 dBm | 100.0% 100.0% 100.0% 96.3% -91 dBm |
| East St. Louis, IL | 100.0% 100.0% 99.7% 91.9% -91 dBm | 99.7% 96.3% 99.4% 79.5% -101 dBm | 100.0% 100.0% 100.0% 100.0% -77 dBm |
| Fairmont City, IL | 100.0% 100.0% 96.7% 94.7% -87 dBm | 99.3% 98.7% 97.4% 62.5% -104 dBm | 100.0% 100.0% 100.0% 99.3% -78 dBm |
| Fairview Heights, IL | 100.0% 100.0% 82.1% 57.2% -97 dBm | 100.0% 99.3% 98.9% 76.5% -103 dBm | 100.0% 100.0% 98.2% 85.3% -86 dBm |
| Fayetteville, IL | 100.0% 100.0% 85.7% 14.3% -107 dBm | 100.0% 100.0% 85.7% 57.1% -119 dBm | 57.1% 57.1% 57.1% 14.3% -100 dBm |
| Floraville, IL | 100.0% 100.0% 50.0% 0.0% -100 dBm | 100.0% 100.0% 100.0% 100.0% -100 dBm | 100.0% 100.0% 100.0% 100.0% -90 dBm |
| Freeburg, IL | 100.0% 100.0% 92.0% 73.9% -94 dBm | 100.0% 100.0% 100.0% 67.6% -101 dBm | 85.2% 85.2% 83.5% 70.5% -88 dBm |
| Lebanon, IL | 100.0% 100.0% 100.0% 98.5% -88 dBm | 100.0% 100.0% 100.0% 84.8% -97 dBm | 100.0% 100.0% 100.0% 97.0% -83 dBm |
| Lenzburg, IL | 100.0% 100.0% 70.4% 37.0% -100 dBm | 100.0% 100.0% 100.0% 29.6% -114 dBm | 100.0% 100.0% 92.6% 70.4% -94 dBm |
| Marissa, IL | 100.0% 100.0% 68.6% 56.0% -91 dBm | 100.0% 100.0% 100.0% 88.0% -103 dBm | 97.1% 96.6% 92.6% 76.6% -83 dBm |
| Mascoutah, IL | 100.0% 100.0% 97.1% 91.7% -90 dBm | 100.0% 100.0% 97.9% 84.2% -108 dBm | 100.0% 100.0% 98.8% 95.4% -83 dBm |
| Millstadt, IL | 98.9% 98.9% 93.3% 78.9% -88 dBm | 100.0% 100.0% 98.9% 86.7% -98 dBm | 98.9% 98.9% 95.6% 82.2% -82 dBm |
| New Athens, IL | 100.0% 100.0% 92.3% 82.7% -85 dBm | 100.0% 100.0% 100.0% 84.6% -96 dBm | 100.0% 100.0% 100.0% 100.0% -78 dBm |
| O’Fallon, IL | 100.0% 100.0% 97.0% 92.4% -89 dBm | 100.0% 100.0% 99.5% 66.8% -104 dBm | 99.5% 99.5% 98.7% 86.3% -86 dBm |
| Paderborn, IL | 100.0% 100.0% 25.0% 0.0% -105 dBm | 100.0% 100.0% 100.0% 75.0% -110 dBm | 100.0% 100.0% 100.0% 50.0% -98 dBm |
| Rentchler, IL | 100.0% 100.0% 100.0% 100.0% -91 dBm | 100.0% 100.0% 100.0% 60.0% -112 dBm | 100.0% 100.0% 100.0% 90.0% -91 dBm |
| Sauget, IL | 100.0% 100.0% 99.2% 98.3% -85 dBm | 100.0% 100.0% 100.0% 63.0% -103 dBm | 100.0% 100.0% 100.0% 95.0% -82 dBm |
| Scott AFB, IL | 100.0% 100.0% 100.0% 94.4% -88 dBm | 100.0% 100.0% 100.0% 47.7% -110 dBm | 100.0% 100.0% 100.0% 97.2% -84 dBm |
| Shiloh, IL | 100.0% 100.0% 100.0% 97.5% -86 dBm | 100.0% 100.0% 99.7% 59.2% -105 dBm | 100.0% 100.0% 99.4% 93.4% -81 dBm |
| Smithton, IL | 100.0% 100.0% 91.7% 83.5% -89 dBm | 100.0% 100.0% 98.2% 75.2% -101 dBm | 100.0% 100.0% 100.0% 95.4% -83 dBm |
| St. Libory, IL | 100.0% 100.0% 50.0% 20.8% -91 dBm | 100.0% 100.0% 87.5% 79.2% -118 dBm | 20.8% 20.8% 8.3% 0.0% -106 dBm |
| Summerfield, IL | 100.0% 100.0% 100.0% 91.7% -96 dBm | 100.0% 100.0% 100.0% 83.3% -112 dBm | 100.0% 100.0% 100.0% 91.7% -84 dBm |
| Swansea, IL | 100.0% 100.0% 100.0% 96.3% -91 dBm | 99.4% 97.0% 99.4% 75.0% -102 dBm | 100.0% 100.0% 100.0% 100.0% -80 dBm |
| Washington Park, IL | 100.0% 100.0% 100.0% 96.8% -96 dBm | 100.0% 100.0% 100.0% 95.2% -97 dBm | 100.0% 100.0% 100.0% 100.0% -75 dBm |
| Collinsville, IL | 100.0% 100.0% 78.3% 70.3% -88 dBm | 99.2% 98.7% 97.4% 79.1% -103 dBm | 100.0% 100.0% 100.0% 94.6% -81 dBm |
| Columbia, IL | 100.0% 100.0% 98.9% 87.8% -95 dBm | 100.0% 100.0% 98.9% 79.8% -108 dBm | 100.0% 100.0% 100.0% 98.1% -85 dBm |
| Hecker, IL | 100.0% 100.0% 0.0% 0.0% -77 dBm | 100.0% 100.0% 100.0% 83.3% -85 dBm | 100.0% 100.0% 100.0% 50.0% -95 dBm |
| Madison, IL | 100.0% 100.0% 89.9% 73.0% -97 dBm | 95.7% 94.2% 90.4% 41.7% -109 dBm | 98.3% 98.3% 93.9% 81.7% -86 dBm |
| New Baden, IL | 100.0% 100.0% 100.0% 97.8% -86 dBm | 100.0% 100.0% 100.0% 71.1% -102 dBm | 100.0% 100.0% 100.0% 100.0% -84 dBm |
| Venice, IL | 100.0% 100.0% 100.0% 97.7% -91 dBm | 100.0% 100.0% 100.0% 43.2% -104 dBm | 100.0% 100.0% 100.0% 100.0% -79 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 St. Clair 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.