Cloudy skies forecast for Monday, April 8, could spell disappointment for many of the millions of North Americans hoping to glimpse the continent’s first total solar eclipse since 2017, possibly turning this spellbinding celestial phenomenon into a dud.

Some regions that more typically experience fair skies in April within the “path of totality” – the narrow corridor where the moon can be seen obscuring the entire face of the sun – appear to have the gloomiest weather outlook for Monday.

Where clear skies prevail, skywatchers along the direct path of the eclipse will be treated to the rare spectacle of the moon appearing as a dark orb creeping in front of the sun, briefly blocking out all but a brilliant halo of light, or corona, around the sun’s outer edge.

The period of up to 4 1/2 minutes of totality in the sky will be ushered in by a number of other eerie eclipse effects.

Some stars will twinkle at midday as twilight abruptly descends, sending temperatures dipping and faint waves of “shadow bands” flickering over the landscape. Birds and other wildlife, reacting to the sudden darkness, may fall silent and still.

An estimated 31.6 million people live in the path of totality, compared with roughly 12 million in the last total solar eclipse that traversed the contiguous United States in August 2017, according to NASA.

Here’s a look at how different places are bracing for the rare celestial event.

– with reports from Reuters/Rappler.com