Cell phone signal is facilitated by the radio frequency (RF) signals cellular towers transmit. If the RF signal is too far or is blocked by obstacles, then a cell phone dead area is created. The most common culprits are:

Cell Phone Tower Distance: RF signals can only travel so far, the further away you are from cell towers the weaker the signal becomes till it eventually disappears.

Topography: Hills, mountains, ridges, and foliage are natural signal barriers. They can absorb or reflect the signal waves, preventing any signal from reaching your phone.

Building Material: Metal, low e-glass, concrete, and brick are the biggest culprits for bad cell phone signal indoors. Signal waves have a hard time penetrating these materials, causing spotty or nonexistent cellular coverage.

Tall Buildings: Cellular signal can be greatly impacted in areas that have numerous tall buildings. Not only are the buildings blocking the RF waves, but also cause reflected signal waves to collide with each other, causing them to weaken and change direction.

Weather: Humidity, rain, and snow can weaken cell phone signal. The water vapor in the air reflects, refracts, and absorbs RF energy, weakening the signal in the process.