Even if there is no rain, if you can hear thunder, you are within striking distance of lightning. Seek shelter immediately.
Good places to take shelter include an automobile (with a metal roof), or a grounded building such as a house. Stay sheltered for 30 minutes after the last flash of lightning.
While indoors, refrain from using, and preferably unplug electronic equipment such as televisions and computers, as well as appliances, (corded) power tools, or (corded) telephones. Refrain from bathing, showering or washing dishes.
If caught outdoors during a thunderstorm, stay away from tall objects such as trees, or any objects or structures that conduct electricity, including metal fences, golf clubs, lawnmowers, bicycles, or umbrellas. Avoid bodies of water.
Avoid being the high point in an open area. Low-lying areas are preferable to hillsides.
If lightning strikes nearby (for example if 30 or fewer seconds elapse between the flash of lightning and the thunderclap) when you are outdoors with no suitable place to take shelter, crouch down, putting your feet together with the heels touching, and your hands over your ears to protect against hearing damage.
If someone has been struck by lightning, call 9‑1‑1 immediately. People who have been struck by lightning may be in shock, and/or suffering from burns. If breathing has stopped, perform CPR until paramedics arrive. People who have been struck by lightning do not carry an electrical charge and can be safely handled right away.