WATCH: With live orchestras and branded merchandise, North America views total solar eclipse

Millions of people across North America are watching, or getting ready to watch, a total solar eclipse — some gazing anxiously at wayward clouds — as the moon begins creeping across the face of the sun in western Mexico, before it blocks it out completely.

The total eclipse is viewable along a path starting in western Mexico and then crossing through the United States and into Canada, and will last more than four minutes in some places.

The Mexican beachside resort town of Mazatlan was the first major viewing spot in North America. Thousands of people gather along the coastal promenade, setting themselves up in deck chairs with eclipse glasses, as an orchestra plays the “Star Wars” theme.

Eclipse fans are gathering in numerous places along the “path of totality.”

In upstate New York, for instance, the total eclipse will occur shortly after 3 p.m. (1900 GMT). At the Frontier Town campground in North Hudson, New York, children run around wearing eclipse T-shirts, while parents set up tables, chairs and beer coolers.

At up to 4 minutes and 28 seconds, this one will last longer than the total eclipse that streaked across parts of the United States in 2017, which clocked in at up to 2 minutes and 42 seconds. According to NASA, total eclipses can last anywhere from 10 seconds to about 7 and 1/2 minutes.

Some other cities along the path of totality include: San Antonio, Austin and Dallas, Texas; Indianapolis, Indiana; Cleveland, Ohio; Erie, Pennsylvania; both Niagara Falls, New York, and Niagara Falls, Ontario, site of the famed waterfall, and Montreal, Quebec.

It will be 20 years before the next eclipse with totality to touch any part of the mainland US — on August 22, 2044.

A partial eclipse will be visible in North America outside the path of totality.