Here's what the life cycle of a cicada looks like: How long do cicadas live above ground? Above ground, cicadas only live for a few weeks. Brood X cicadas are expected to be gone before Labor Day, according to Pest World. Are cicadas dangerous? When were cicadas in NJ last? The Brood II, also known as the "East Coast Brood" came to New Jersey and eight other places in the eastern United States in 2013. The next emergence of the Brood II, which has a 17-year life cycle, is not expected until 2030. Why are the cicadas so loud this year? Male cicadas sing loudly, by flexing small drum-like organs in their abdomens, to attract females.