As you may know, the city of Manhattan is laid out in a grid pattern. Twice a year, when the sun sets, it aligns perfectly with the east-west grid of certain main streets: 14th, 23rd, 34th, 42nd and 57th Streets.
During Manhattanhenge, a viewer on one of these streets can watch the sun setting directly opposite in New Jersey.
Astrophysicist, Neil deGrasse Tyson of the American Museum of Natural History is credited with popularizing this phenomena.
This year, according to Dr. deGrasse Tyson, the remaining dates for Manhattanhenge July 11th and 12th (it was also possible to see it on May 30th and 31st). On July 11th, the full sun will be visible on the horizon, whereas on July 12th, only half will be seen.
So, if you’re in or around New York City in July, make sure to look out for Manhattanhenge.
But Manhattanhenge is not limited to Manhattan alone. According to Wikipedia, Chicagohenge will happen on September 25th, Torontohenge on October 25th, and Montrealhenge on July 12th.