The visual effect known as Manhattanhenge returns to New York City this week but PM thunderstorms and clouds may obscure the phenomena. The event—which was first named and noticed by Neil deGrasse Tyson—happens four times a year, twice with a half sun and twice with a full sun. It occurs when the sunset aligns perfectly with the city’s grid system, illuminating both the north and south sides of every cross street of the borough’s grid.

“It is a unique  urban phenomenon in the world, if not the universe,” said  Tyson.

Clouds and showers interfered with the first events of 2018 which began on May 29, at 8:13pm.

The final full Manhattenhenge of 2017 will happen on Wednesday, July 12, at 8:20pm where the full sun will be visible. Half the sun will be visible in the last event of the year on  Thursday, July 13 at 8:21pm.

For the best view of Manhattanhenge, you should be as far east as possible, but be sure to pick a street where the view is clear across to New Jersey and the Hudson River. The best views  are on 57th, 42nd, 34th, 23rd, and 14th street.