Day County, SD Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in Day County, SD

Coverage rankings for Day County, SD

T-Mobile 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
1T-Mobile81.694.0%94.0%79.1%45.3% -96 dBm
2AT&T80.097.7%97.6%75.1%54.1% -115 dBm
3Verizon58.199.3%99.3%6.9%1.2% -94 dBm

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

Cell phone coverage map for Day County, SD

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 Day County, SD

#1

T-Mobile

Coverage Score 81.6
In Day County, SD
Overall
94.0%
4G LTE
94.0%
5G
79.1%
Fast 5G
45.3%
Average Signal -96 dBm
#2

AT&T

Coverage Score 80.0
In Day County, SD
Overall
97.7%
4G LTE
97.6%
5G
75.1%
Fast 5G
54.1%
Average Signal -115 dBm
#3

Verizon

Coverage Score 58.1
In Day County, SD
Overall
99.3%
4G LTE
99.3%
5G
6.9%
Fast 5G
1.2%
Average Signal -94 dBm
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Coverage by city in Day County, SD

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

CityVerizonAT&TT-Mobile
Andover, SD 100.0% 100.0% 85.7% 0.0% -103 dBm 100.0% 100.0% 100.0% 85.7% -111 dBm 100.0% 100.0% 100.0% 71.4% -94 dBm
Bristol, SD 100.0% 100.0% 0.0% 0.0% -85 dBm 100.0% 100.0% 100.0% 100.0% -106 dBm 100.0% 100.0% 100.0% 100.0% -87 dBm
Butler, SD 100.0% 100.0% 0.0% 0.0% -94 dBm 100.0% 100.0% 85.7% 57.1% -119 dBm 100.0% 100.0% 100.0% 57.1% -96 dBm
Enemy Swim, SD 100.0% 100.0% 37.5% 0.0% -100 dBm 100.0% 100.0% 100.0% 95.8% -111 dBm 66.7% 66.7% 41.7% 0.0% -103 dBm
Grenville, SD 100.0% 100.0% 0.0% 0.0% -98 dBm 100.0% 100.0% 100.0% 100.0% -112 dBm 66.7% 66.7% 16.7% 0.0% -103 dBm
Pierpont, SD 100.0% 100.0% 0.0% 0.0% -100 dBm 100.0% 100.0% 100.0% 25.0% -120 dBm 100.0% 100.0% 100.0% 50.0% -95 dBm
Roslyn, SD 100.0% 100.0% 0.0% 0.0% -87 dBm 100.0% 100.0% 66.7% 33.3% -117 dBm 66.7% 66.7% 50.0% 16.7% -100 dBm
Waubay, SD 100.0% 100.0% 0.0% 0.0% -65 dBm 100.0% 100.0% 100.0% 87.9% -92 dBm 90.9% 90.9% 60.6% 9.1% -102 dBm
Webster, SD 100.0% 100.0% 0.0% 0.0% -78 dBm 100.0% 100.0% 79.5% 79.5% -113 dBm 100.0% 100.0% 100.0% 100.0% -80 dBm
Ortley, SD 100.0% 100.0% 0.0% 0.0% -91 dBm 100.0% 100.0% 100.0% 100.0% -104 dBm 98.1% 98.1% 76.9% 21.2% -97 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 Day County, SD 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.