What To Expect During The Eclipse, Based On Where You Are

This coming Monday, August 21, a dark shadow will be cast across the United States. Apocalyptic overtones aside: No matter where you are, you will see a solar eclipse, though the completion of that eclipse will vary by city.

Most of the country will see a partial eclipse; those lucky enough to live or travel to a city that falls within the narrow path of totality, which stretches in an arc from Oregon to South Carolina, will see the moon completely cover the sun for two minutes and 40 seconds. If you're in that path, you'll also see what scientists describe as the diamond ring effect: The moment immediately before the moon fully covers the sun, when there is a faint ring of light and final flash of the sun. Either way though, you'll need to wear solar eclipse glasses if you're planning to observe.

To fully prepare, you'll need to watch a few things: The weather (clouds could get in the way of your views), the traffic if you're traveling, and the time that the eclipse will hit your region. Here's how to keep an eye on all three.

The Federal High Administration estimates that about 200 million people live within a day's drive of the eclipse. This means that you can expect traffic jams on par with the usual packed state of L.A. roads — or worse. The FHA advises people to be at their viewing location at least a few hours prior to the beginning of the partial eclipse, noting that many state and local authorities will be setting up roadblocks.

Expect that traffic will be at its worst right after the moment of totality: Just like at the end of a big concert or conclusion of fourth of July fireworks, everyone will look to make a quick exit.

Head here to see the FHA's eclipse map, with detailed information about viewing locations in each of the states that falls within the path of totality.

As we get closer to the eclipse, head to the National Weather Service's eclipse website for updates on what the weather will be in your area. If there's a thunderstorm, your view could be obstructed.

There are multiple ways to track when the eclipse will occur in your region. On your phone, three apps use your location to tell you exactly when a partial or total eclipse will begin: Timeanddate.com's Solar Eclipse 2017, the Smithsonian Eclipse 2017, and Eclipse Safari.

All of the apps are free, but for $0.99 you can upgrade to a premium version of Timeanddate.com's app which will include additional details — such as when the eclipse will reach its peak in your area. It's worth it if you want to know the best time to head outside. Interactive maps in each of the apps will also give you a sense of how the eclipse will look based on where you are.

Online, there are a few interactive maps worth using. The Eclipse Megamovie 2017 Simulator — a joint project between Google and The University of California, Berkeley — is one of the best. Simply punch in your town or zip code, and the corresponding infographic will adjust to show you when the moon will partially or totally cover the sun. This interactive Google Map and interactive eclipse "tour" from the Great American Eclipse are also useful tools. NASA's video (below) offers a view of the eclipse's path as it moves from west to east across the U.S.