Dry, mostly cloudless conditions expected for 2018's final Manhattanhenge

New Yorkers and tourists may be in for a treat as Manhattan's famed sunset prepares to bathe the borough in a dazzling glow for the final time in 2018.

Clouds got in the way of amazing photos for Manhattanhenge's first two occurrences of the year in May. However, AccuWeather anticipates dry, likely cloud-free conditions as the unique phenomenon happens for the third and fourth time on July 12 and 13, respectively.

"I'd say they're in pretty good shape for Thursday evening," said AccuWeather Senior Meteorologist Dave Dombek. "Odds are that it's going to be clear to partly cloudy."

While Friday is expected to be sunny during the day, spectators may have to keep an eye on high clouds that could roll in around sunset, according to Dombek.

Manhattanhenge from 42nd Street - Getty Images
Manhattanhenge from 42nd Street - Getty Images

A view of the Manhattanhenge sunset from 42nd Street in New York City. (Photo/Josh Namdar/Getty Images)

"If that's the case, then the sun would kind of have more of a milky appearance rather than the puffy, lower-level cumulative clouds," he added.

The Manhattanhenge sunset, which happens when the sunset perfectly aligns with the east- and westward roads of Manhattan's grid, is set to occur at 8:20 p.m. EDT Thursday and 8:21 p.m. EDT Friday.

Temperatures around these times on Thursday and Friday are expected to hover around the upper 70s F, Dombek said.

"The humidity both of those days really won't be too bad at all," he added.

The thousands of observers anticipated to flood Manhattan's streets for the event are advised to arrive a half-hour early.

Those looking to see the full sun on the borough's grid should check out the celestial display on July 12, while the half sun will be visible on the grid on Friday.

On both days, spectators will hopefully be treated to a stunning view of the sunset lighting up the sides of buildings along the north and south portions of Manhattan's streets.

In 2002, astrophysicist Neil deGrasse Tyson coined the term "Manhattanhenge," which derives its name from the popular Stonehenge summer solstice event that occurred just weeks ago in the United Kingdom on June 21.

Similar "-henge" events take place in different cities including Chicago, Montreal and Toronto throughout the year.

"Note that any city crossed by a rectangular grid can identify days where the setting sun aligns with their streets," deGrasse Tyson wrote on his blog.

A closer look at such cities, however, shows them to be less than ideal for this purpose when compared with New York City's Manhattan, according to deGrasse Tyson.

"Beyond the grid, you need a clear view to the horizon, as Manhattan has across the Hudson River to New Jersey, and tall buildings that line the streets create a vertical channel to frame the setting sun, creating a striking photographic opportunity," he wrote.

For the best viewing effect, deGrasse Tyson recommends finding a location as far east in Manhattan as possible, ensuring that New Jersey is still visible when looking west across the avenues.

Clear cross streets include 14th, 23rd, 34th, 42nd, 57th and several adjacent streets, while the Empire State and Chrysler buildings on 34th and 42nd streets make for a great sunset effect, he wrote.

While spectators may be caught up in the excitement of taking breathtaking photos of Manhattanhenge, they should make sure that they're capturing the sunset safely to avoid any vision damage.

"While rare, it is possible that if you were to stare directly at the sun for several continuous minutes during a sunset that it could cause mild solar retinopathy," said ophthalmologist Dr. Ming Wang of the Nashville-based Wang Vision 3D Cataract and LASIK Center.

"For this reason, it's best to look away from the actual sun and look at the surrounding atmosphere, clouds and light rather than directly at the sun for the entire viewing time," Wang said.