San Bernardino County, CA Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in San Bernardino County, CA

Coverage rankings for San Bernardino County, CA

T-Mobile currently ranks first for coverage in this area, with a coverage score of 58.9. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.

RankCarrierScoreOverall4G LTE5GFast 5GAverage Signal
1T-Mobile58.954.8%54.6%48.1%33.9% -93 dBm
2Verizon58.371.8%71.0%33.0%24.4% -97 dBm
3AT&T56.774.5%74.5%51.4%48.5% -115 dBm

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

Cell phone coverage map for San Bernardino County, CA

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 San Bernardino County, CA

#1

T-Mobile

Coverage Score 58.9
In San Bernardino County, CA
Overall
54.8%
4G LTE
54.6%
5G
48.1%
Fast 5G
33.9%
Average Signal -93 dBm
#2

Verizon

Coverage Score 58.3
In San Bernardino County, CA
Overall
71.8%
4G LTE
71.0%
5G
33.0%
Fast 5G
24.4%
Average Signal -97 dBm
#3

AT&T

Coverage Score 56.7
In San Bernardino County, CA
Overall
74.5%
4G LTE
74.5%
5G
51.4%
Fast 5G
48.5%
Average Signal -115 dBm
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Coverage by city in San Bernardino County, CA

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

CityVerizonAT&TT-Mobile
Adelanto, CA 100.0% 100.0% 99.8% 97.5% -87 dBm 99.9% 99.9% 96.5% 91.7% -115 dBm 100.0% 100.0% 99.8% 98.9% -77 dBm
Amboy, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Angelus Oaks, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Apple Valley, CA 100.0% 100.0% 99.9% 99.0% -85 dBm 99.9% 99.9% 99.2% 90.5% -107 dBm 100.0% 100.0% 99.8% 94.0% -85 dBm
Baker, CA 100.0% 100.0% 0.0% 0.0% -71 dBm 100.0% 100.0% 100.0% 100.0% -98 dBm 100.0% 100.0% 100.0% 100.0% -73 dBm
Barstow, CA 100.0% 100.0% 98.9% 96.0% -81 dBm 100.0% 100.0% 99.8% 98.9% -103 dBm 100.0% 100.0% 99.9% 97.1% -84 dBm
Big Bear City, CA 89.2% 88.8% 74.7% 61.3% -94 dBm 85.1% 85.1% 66.3% 66.0% -106 dBm 75.1% 75.1% 70.3% 57.7% -87 dBm
Big Bear Lake, CA 100.0% 100.0% 100.0% 92.0% -87 dBm 100.0% 100.0% 99.3% 99.3% -100 dBm 99.3% 99.3% 98.6% 93.5% -82 dBm
Big River, CA 100.0% 100.0% 96.6% 48.9% -100 dBm 100.0% 100.0% 93.1% 91.4% -111 dBm 99.1% 99.1% 94.8% 76.4% -89 dBm
Bloomington, CA 100.0% 100.0% 100.0% 100.0% -80 dBm 100.0% 100.0% 100.0% 94.9% -105 dBm 100.0% 100.0% 100.0% 100.0% -75 dBm
Bluewater, CA 100.0% 100.0% 82.6% 73.9% -90 dBm 100.0% 100.0% 87.0% 87.0% -110 dBm 100.0% 100.0% 39.1% 39.1% -77 dBm
Cedar Glen, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Cedarpines Park, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Chino, CA 100.0% 100.0% 99.5% 97.3% -85 dBm 100.0% 100.0% 99.8% 98.2% -106 dBm 100.0% 100.0% 100.0% 98.2% -81 dBm
Chino Hills, CA 93.8% 93.0% 80.6% 62.1% -96 dBm 85.9% 85.8% 69.5% 67.2% -111 dBm 84.7% 84.7% 76.3% 62.4% -89 dBm
Colton, CA 100.0% 100.0% 100.0% 100.0% -82 dBm 99.7% 99.7% 99.4% 89.3% -104 dBm 99.4% 99.4% 98.6% 96.0% -79 dBm
Crestline, CA 99.0% 99.0% 78.5% 51.0% -99 dBm 81.8% 80.5% 61.3% 48.3% -113 dBm 92.4% 91.7% 85.4% 67.5% -92 dBm
Daggett, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Earp, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Essex, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Fawnskin, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Fontana, CA 100.0% 100.0% 99.6% 97.8% -82 dBm 100.0% 100.0% 99.8% 95.2% -102 dBm 100.0% 100.0% 100.0% 99.8% -78 dBm
Forest Falls, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Fort Irwin, CA 100.0% 100.0% 100.0% 98.7% -79 dBm 100.0% 100.0% 98.7% 95.3% -104 dBm 99.3% 99.3% 98.7% 93.3% -83 dBm
Grand Terrace, CA 100.0% 100.0% 72.4% 72.4% -83 dBm 100.0% 100.0% 100.0% 73.7% -107 dBm 100.0% 100.0% 100.0% 100.0% -77 dBm
Green Valley Lake, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Helendale, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Hesperia, CA 99.7% 99.6% 94.6% 87.9% -86 dBm 98.8% 98.8% 96.7% 91.2% -106 dBm 99.3% 99.2% 97.6% 87.9% -84 dBm
Highland, CA 100.0% 99.7% 99.7% 96.7% -83 dBm 98.5% 98.5% 95.5% 87.5% -106 dBm 98.7% 98.7% 96.0% 88.0% -84 dBm
Hinkley, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Homestead Valley, CA 98.7% 98.7% 76.9% 39.9% -98 dBm 78.9% 78.9% 32.0% 31.8% -119 dBm 99.6% 99.6% 99.1% 97.2% -79 dBm
Joshua Tree, CA 99.2% 99.1% 90.0% 81.0% -93 dBm 99.7% 99.7% 95.2% 90.2% -110 dBm 92.3% 92.3% 82.8% 62.6% -94 dBm
Lake Arrowhead, CA 100.0% 100.0% 91.2% 71.0% -94 dBm 95.2% 95.2% 73.8% 70.8% -107 dBm 94.2% 94.2% 87.9% 74.1% -89 dBm
Landers, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Lenwood, CA 100.0% 100.0% 100.0% 100.0% -84 dBm 100.0% 100.0% 100.0% 100.0% -105 dBm 100.0% 100.0% 100.0% 97.7% -89 dBm
Loma Linda, CA 100.0% 100.0% 100.0% 94.3% -85 dBm 99.0% 99.0% 87.0% 74.1% -108 dBm 97.9% 97.9% 93.8% 83.4% -84 dBm
Lucerne Valley, CA 99.6% 98.9% 93.5% 83.8% -91 dBm 97.9% 97.9% 93.1% 89.1% -115 dBm 98.6% 98.6% 96.4% 83.5% -88 dBm
Ludlow, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Lytle Creek, CA 97.0% 97.0% 85.0% 67.7% -98 dBm 12.8% 12.8% 3.8% 3.0% -119 dBm 36.1% 36.1% 23.3% 8.3% -101 dBm
Mentone, CA 100.0% 100.0% 100.0% 97.7% -87 dBm 100.0% 100.0% 96.2% 93.2% -108 dBm 96.2% 96.2% 87.2% 61.7% -95 dBm
Montclair, CA 100.0% 100.0% 100.0% 100.0% -84 dBm 100.0% 100.0% 100.0% 100.0% -97 dBm 100.0% 100.0% 100.0% 100.0% -76 dBm
Morongo Valley, CA 90.6% 90.4% 78.9% 63.4% -95 dBm 83.4% 83.4% 61.2% 60.6% -115 dBm 69.5% 69.5% 54.7% 26.0% -98 dBm
Mountain View Acres, CA 100.0% 100.0% 100.0% 100.0% -79 dBm 100.0% 100.0% 100.0% 91.7% -108 dBm 100.0% 100.0% 100.0% 97.2% -85 dBm
Mt Baldy, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Muscoy, CA 100.0% 100.0% 100.0% 100.0% -84 dBm 100.0% 100.0% 100.0% 75.4% -110 dBm 100.0% 100.0% 100.0% 100.0% -76 dBm
Needles, CA 100.0% 100.0% 96.5% 72.3% -92 dBm 100.0% 100.0% 100.0% 100.0% -103 dBm 99.8% 99.4% 98.8% 93.5% -85 dBm
Newberry Springs, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Nipton, CA N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Oak Glen, CA 98.8% 98.5% 91.1% 54.8% -99 dBm 78.2% 78.2% 29.2% 23.4% -119 dBm 65.5% 65.5% 50.8% 17.2% -100 dBm
Oak Hills, CA 100.0% 100.0% 99.6% 97.0% -83 dBm 100.0% 100.0% 92.2% 75.0% -114 dBm 100.0% 100.0% 98.9% 91.1% -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 San Bernardino County, CA 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.