Tonight will be the last chance for New Yorkers to see "Manhattanhenge" this year, but clouds could obscure the view.
Manhattanhenge occurs when the setting sun perfectly aligns with New York's east to west skyline, LiveScience reported.
The spectacle takes place four times a year, there are two half sunsets and two full. The last time it showed up was on May 28 and 29.
Manhattanhenge was supposed to be visible last evening, but rainclouds obscured the view. There's one more chance to see it tonight, but there's a 30 percent chance of rain.
The phenomenon will take place at 8:24 p.m. Astrophysicist Neil deGrasse Tyson, who came up with the name "Manhattanhhenge" in 2001, said to go outside half an hour earlier than the sunset for the best show.
"For the best effect, position yourself as far east in Manhattan as possible. But ensure that when you look west across the avenues you can still see New Jersey," Tyson, director of the American Museum of Natural History's Hayden Planetarium wrote in a museum blog post.
The best views of the sunset are on wider streets like 14th, 23rd, 34th, 42nd, and 57th.
"The Empire State building and the Chrysler building render 34th street and 42nd streets especially striking vistas," Tyson said.
Tyson suggested shutting down streets to control traffic as droves of people gather to watch the sunset. The crows have gotten so large in the past that tweeters have referred to it as "peoplehenge," NBC News reported.
On Thursday night 79th street was apparently shut down for a pre-manhattanhenge viewing party at the American Museum of Natural History.
Other cities such as Baltimore and Chicago that have similar grid patterns also experience the phenomenon.
Manhattanhenge enthusiasts such as Andrew Dallos, a producer for MSNBC, is hoping the clouds won't ruin the event.
"Keeping my fingers crossed," he tweeted, according NBC News.
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