The visual effect known as Manhattanhenge returns to New York City. 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 are forecast to interfere with the first event which will happen tonight, May 29, at 8:13pm. During this event, half the sun is usually visible above the horizon while the other half is hidden below. The weather should cooperate more with Tuesday’s 8:13pm event; then, the full sphere of the sun will be visible above the horizon.

If you’re not in town and/or if inclement weather obstructs the view this month, you’ll have another chance to see the phenomena in July. The next event happens 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 the following day, 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.