St. Mary County, LA Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in St. Mary County, LA

Coverage rankings for St. Mary County, LA

AT&T currently ranks first for coverage in this area, with a coverage score of 78.1. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.

RankCarrierScoreOverall4G LTE5GFast 5GAverage Signal
1AT&T78.191.7%90.9%82.1%48.7% -109 dBm
2T-Mobile52.955.1%55.1%42.3%26.4% -95 dBm
3Verizon45.474.7%74.7%0.0%0.0% -95 dBm

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

Cell phone coverage map for St. Mary County, LA

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 St. Mary County, LA

#1

AT&T

Coverage Score 78.1
In St. Mary County, LA
Overall
91.7%
4G LTE
90.9%
5G
82.1%
Fast 5G
48.7%
Average Signal -109 dBm
#2

T-Mobile

Coverage Score 52.9
In St. Mary County, LA
Overall
55.1%
4G LTE
55.1%
5G
42.3%
Fast 5G
26.4%
Average Signal -95 dBm
#3

Verizon

Coverage Score 45.4
In St. Mary County, LA
Overall
74.7%
4G LTE
74.7%
5G
0.0%
Fast 5G
0.0%
Average Signal -95 dBm
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Coverage by city in St. Mary County, LA

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

CityVerizonAT&TT-Mobile
Amelia, LA 100.0% 100.0% 0.0% 0.0% -77 dBm 100.0% 100.0% 100.0% 100.0% -99 dBm 100.0% 100.0% 100.0% 100.0% -77 dBm
Baldwin, LA 100.0% 100.0% 0.0% 0.0% -84 dBm 100.0% 100.0% 100.0% 85.5% -91 dBm 100.0% 100.0% 100.0% 96.1% -82 dBm
Bayou Vista, LA 100.0% 100.0% 0.0% 0.0% -79 dBm 100.0% 100.0% 100.0% 72.5% -99 dBm 100.0% 100.0% 100.0% 100.0% -79 dBm
Berwick, LA 100.0% 100.0% 0.0% 0.0% -86 dBm 100.0% 100.0% 100.0% 90.4% -97 dBm 100.0% 100.0% 100.0% 94.9% -83 dBm
Centerville, LA 100.0% 100.0% 0.0% 0.0% -88 dBm 100.0% 100.0% 100.0% 54.5% -106 dBm 100.0% 100.0% 100.0% 100.0% -68 dBm
Charenton, LA 100.0% 100.0% 0.0% 0.0% -94 dBm 100.0% 100.0% 100.0% 94.7% -96 dBm 100.0% 100.0% 100.0% 100.0% -76 dBm
Franklin, LA 100.0% 100.0% 0.0% 0.0% -85 dBm 100.0% 100.0% 100.0% 76.0% -96 dBm 100.0% 100.0% 98.7% 79.1% -83 dBm
Glencoe, LA 86.7% 86.7% 0.0% 0.0% -100 dBm 100.0% 100.0% 100.0% 60.0% -117 dBm 13.3% 13.3% 6.7% 0.0% -105 dBm
Morgan City, LA 100.0% 100.0% 0.0% 0.0% -75 dBm 100.0% 100.0% 100.0% 86.1% -89 dBm 100.0% 100.0% 100.0% 100.0% -79 dBm
Patterson, LA 100.0% 100.0% 0.0% 0.0% -85 dBm 100.0% 100.0% 100.0% 100.0% -91 dBm 100.0% 100.0% 100.0% 100.0% -82 dBm
Siracusaville, LA 100.0% 100.0% 0.0% 0.0% -78 dBm 100.0% 100.0% 100.0% 100.0% -94 dBm 100.0% 100.0% 100.0% 63.2% -97 dBm
Sorrel, LA 100.0% 100.0% 0.0% 0.0% -79 dBm 100.0% 100.0% 100.0% 88.5% -102 dBm 100.0% 100.0% 80.8% 44.2% -98 dBm
Jeanerette, LA 100.0% 100.0% 0.0% 0.0% -85 dBm 100.0% 100.0% 100.0% 77.8% -96 dBm 100.0% 100.0% 100.0% 100.0% -85 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. Mary County, LA 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.