Boulder County, CO Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in Boulder County, CO

Coverage rankings for Boulder County, CO

T-Mobile currently ranks first for coverage in this area, with a coverage score of 62.6. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.

RankCarrierScoreOverall4G LTE5GFast 5GAverage Signal
1T-Mobile62.660.0%59.1%54.9%41.4% -91 dBm
2Verizon57.560.4%60.2%43.1%32.7% -94 dBm
3AT&T55.068.8%68.7%45.9%27.2% -113 dBm

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

Cell phone coverage map for Boulder County, CO

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.

Loading coverage map...

Cell phone coverage by network in Boulder County, CO

#1

T-Mobile

Coverage Score 62.6
In Boulder County, CO
Overall
60.0%
4G LTE
59.1%
5G
54.9%
Fast 5G
41.4%
Average Signal -91 dBm
#2

Verizon

Coverage Score 57.5
In Boulder County, CO
Overall
60.4%
4G LTE
60.2%
5G
43.1%
Fast 5G
32.7%
Average Signal -94 dBm
#3

AT&T

Coverage Score 55.0
In Boulder County, CO
Overall
68.8%
4G LTE
68.7%
5G
45.9%
Fast 5G
27.2%
Average Signal -113 dBm
Sponsored US Mobile

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.

Choose your network
Dark Star Light Speed Warp 5G
Unlimited plans from
$22.50/mo
Phone + home internet bundle from
$47/mo
Shop US Mobile

Pricing, network access, switching terms, and home internet availability may vary.

Coverage by city in Boulder County, CO

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

CityVerizonAT&TT-Mobile
Allenspark, CO 0.7% 0.7% 0.0% 0.0% -110 dBm 1.1% 1.1% 0.0% 0.0% -120 dBm 1.5% 1.5% 0.7% 0.0% -105 dBm
Altona, CO 89.2% 86.5% 78.4% 64.9% -97 dBm 75.7% 75.7% 62.2% 8.1% -119 dBm 73.0% 73.0% 67.6% 48.6% -93 dBm
Bark Ranch, CO N/A N/A N/A N/A N/A 25.0% 25.0% 5.0% 0.0% -120 dBm 15.0% 10.0% 15.0% 0.0% -100 dBm
Bonanza Mountain Estates, CO 100.0% 100.0% 0.0% 0.0% -97 dBm 100.0% 100.0% 100.0% 100.0% -113 dBm 100.0% 100.0% 100.0% 0.0% -97 dBm
Boulder, CO 100.0% 100.0% 95.7% 83.0% -87 dBm 100.0% 100.0% 79.8% 53.9% -107 dBm 99.7% 99.7% 97.4% 87.4% -84 dBm
Crisman, CO 56.3% 56.3% 3.1% 0.0% -110 dBm 31.3% 31.3% 9.4% 0.0% -119 dBm 15.6% 12.5% 9.4% 0.0% -100 dBm
Eldora, CO 57.6% 57.6% 13.0% 10.9% -102 dBm 53.3% 53.3% 33.7% 28.3% -117 dBm 34.8% 34.8% 20.7% 8.7% -100 dBm
Eldorado Springs, CO 100.0% 100.0% 85.2% 55.7% -98 dBm 90.2% 90.2% 65.6% 36.1% -116 dBm 95.1% 95.1% 91.8% 78.7% -92 dBm
Glendale, CO 34.5% 34.5% 24.1% 0.0% -102 dBm 37.9% 37.9% 13.8% 0.0% -120 dBm 37.9% 34.5% 37.9% 24.1% -93 dBm
Gold Hill, CO 46.8% 46.8% 8.5% 0.0% -105 dBm 59.6% 59.6% 6.4% 2.1% -120 dBm 34.0% 34.0% 31.9% 17.0% -96 dBm
Gunbarrel, CO 100.0% 100.0% 99.3% 95.0% -84 dBm 100.0% 100.0% 44.0% 35.5% -101 dBm 100.0% 100.0% 99.3% 74.5% -92 dBm
Hidden Lake, CO 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
Jamestown, CO 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
Lafayette, CO 100.0% 100.0% 97.1% 92.3% -86 dBm 100.0% 100.0% 87.0% 72.1% -113 dBm 100.0% 100.0% 99.0% 88.0% -84 dBm
Lazy Acres, CO 79.3% 77.7% 45.5% 9.9% -104 dBm 85.1% 85.1% 41.3% 1.7% -118 dBm 61.2% 60.3% 47.9% 29.8% -96 dBm
Leyner, CO 100.0% 100.0% 100.0% 100.0% -88 dBm 100.0% 100.0% 100.0% 100.0% -120 dBm 100.0% 100.0% 100.0% 60.0% -96 dBm
Longmont, CO 100.0% 100.0% 97.2% 85.0% -86 dBm 100.0% 100.0% 100.0% 76.7% -105 dBm 100.0% 100.0% 99.7% 88.7% -83 dBm
Louisville, CO 100.0% 100.0% 95.6% 79.7% -87 dBm 99.5% 98.4% 89.0% 59.3% -109 dBm 100.0% 100.0% 98.4% 81.9% -86 dBm
Lyons, CO 100.0% 100.0% 93.3% 60.0% -91 dBm 100.0% 100.0% 96.7% 90.0% -95 dBm 100.0% 100.0% 100.0% 100.0% -74 dBm
Mountain Meadows, CO 80.0% 80.0% 10.0% 0.0% -109 dBm 92.5% 92.5% 17.5% 2.5% -120 dBm 37.5% 37.5% 25.0% 17.5% -99 dBm
Nederland, CO 100.0% 100.0% 67.6% 55.9% -89 dBm 100.0% 100.0% 100.0% 91.2% -97 dBm 91.2% 91.2% 82.4% 73.5% -80 dBm
Niwot, CO 100.0% 100.0% 98.9% 87.2% -82 dBm 100.0% 100.0% 89.4% 83.0% -104 dBm 100.0% 100.0% 100.0% 90.4% -87 dBm
Paragon Estates, CO 100.0% 100.0% 100.0% 100.0% -84 dBm 100.0% 100.0% 91.4% 40.0% -114 dBm 100.0% 100.0% 97.1% 77.1% -91 dBm
Pine Brook Hill, CO 87.0% 87.0% 56.5% 39.1% -99 dBm 92.8% 92.8% 47.8% 4.3% -116 dBm 81.2% 81.2% 73.9% 55.1% -93 dBm
Pinecliffe, CO 6.3% 6.3% 0.0% 0.0% -110 dBm 100.0% 100.0% 93.8% 93.8% -112 dBm N/A N/A N/A N/A N/A
Seven Hills, CO 41.7% 41.7% 16.7% 0.0% -108 dBm 58.3% 58.3% 0.0% 0.0% -119 dBm 8.3% 8.3% 0.0% 0.0% -100 dBm
St. Ann Highlands, CO 18.8% 18.8% 3.1% 3.1% -107 dBm 81.3% 81.3% 31.3% 21.9% -119 dBm 12.5% 12.5% 6.3% 3.1% -100 dBm
Sugarloaf, CO 85.4% 85.4% 14.6% 0.0% -106 dBm 85.4% 85.4% 41.7% 12.5% -119 dBm 70.8% 68.8% 62.5% 45.8% -95 dBm
Sunshine, CO 87.2% 87.2% 33.3% 0.0% -106 dBm 66.7% 66.7% 28.2% 0.0% -118 dBm 48.7% 48.7% 41.0% 35.9% -95 dBm
Superior, CO 100.0% 100.0% 88.0% 51.1% -94 dBm 100.0% 100.0% 100.0% 73.9% -98 dBm 100.0% 100.0% 75.0% 55.4% -87 dBm
Tall Timber, CO 75.0% 75.0% 16.7% 0.0% -109 dBm 66.7% 66.7% 8.3% 0.0% -119 dBm 41.7% 33.3% 33.3% 8.3% -96 dBm
Valmont, CO 100.0% 100.0% 85.7% 57.1% -87 dBm 100.0% 100.0% 0.0% 0.0% -103 dBm 100.0% 100.0% 100.0% 85.7% -83 dBm
Ward, CO 14.3% 14.3% 0.0% 0.0% -110 dBm 71.4% 71.4% 14.3% 0.0% -120 dBm 7.1% 7.1% 7.1% 0.0% -100 dBm
Broomfield, CO 100.0% 100.0% 99.5% 93.4% -85 dBm 100.0% 100.0% 99.1% 81.8% -104 dBm 100.0% 100.0% 99.2% 93.4% -82 dBm
Coal Creek, CO 36.6% 36.6% 0.0% 0.0% -108 dBm 76.1% 75.6% 38.0% 29.6% -115 dBm 30.0% 29.6% 26.3% 8.9% -100 dBm
Erie, CO 100.0% 100.0% 77.4% 69.8% -86 dBm 100.0% 99.8% 95.8% 72.8% -108 dBm 100.0% 100.0% 98.4% 88.0% -85 dBm
Rollinsville, CO 13.3% 13.3% 0.0% 0.0% -110 dBm 100.0% 100.0% 90.0% 90.0% -110 dBm 6.7% 6.7% 0.0% 0.0% -105 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 Boulder County, CO 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.