Is It Dangerous to Talk on Any Phone During Lightning?by Micah McDunnigan
Lightning storms can be magnificent sights, but whether or not you should pick up the phone to tell a friend what you're seeing depends on what kind of phone you're reaching for. While cell phones and cordless phones are safe to use, using corded landlines leave you vulnerable to being electrocuted by a lightning strike.
It is extremely dangerous to talk on a corded landline phone during a storm. If lightning strikes your home, or power lines around your home, the current can travel through the wiring to your phone. If you are holding the phone at this time, you'll be hit with the full strength of the electrical current. According to the National Weather Service, about five percent of people struck by lightning are struck while talking on a corded telephone.
Cell phones, and landlines with cordless phones, do not carry the same risk as phones with cords. With corded phones, there is a conductive path a lightning bolt could follow from the location it originally strikes to your body. Cell phones and cordless phones, however, do not provide this kind of conductive path. This makes them safe to use during lightning storms. However, a cell phone plugged into its charger carries the same danger during lightning storms as a corded phone.
Electronics in General
Phones aren't the only things that can provide a path from a lightning strike to your person. Using any electronic devices that plug into the wall can present the same risk. This is why it is important to have your electronic devices plugged into surge protectors, especially if you live in an area that gets a lot of lightning.
Cell phones and cordless phones don't increase your chances of being struck by lightning, but they do not make it safe to be outside during a lightning storm. Lightning can strike you even if you are not the tallest thing around. According to the National Weather Service, even if lightning only strikes near you, it can radiate a current which can be fatal within 100 feet of the strike. The safest place you can be during a lightning storm is indoors.