One of the most incredible events we will encounter in our lifetimes will soon be upon us, with the total solar eclipse of 2017 set for Aug. 21. But something truly shocking will take place during that event if you’re in that narrow band stretching from Oregon to South Carolina, as experts say you will likely feel a sudden plunge in the temperature.

And that temperature drop could be absolutely huge. During the 1834 total sola reclipse, the temperature dipped by an astonishing 28 degrees Fahrenheit, from 78 to 50 degrees, during the eclipse. It would add a truly startling new level to witnessing the entire landscape go black.

The temperature change will probably differ greatly depending on where you are and what time of year it is. More than likely, the temperature difference will be similar to how it feels at midday compared to the temperature just after sunset on the same day.

“On Monday, August 21, 2017, all of North America will be treated to an eclipse of the sun. Anyone within the path of totality can see one of nature’s most awe inspiring sights – a total solar eclipse,” NASA states on their website. “This path, where the moon will completely cover the sun and the sun’s tenuous atmosphere – the corona – can be seen, will stretch from Salem, Oregon to Charleston, South Carolina. Observers outside this path will still see a partial solar eclipse where the moon covers part of the sun’s disk. NASA created this website to provide a guide to this amazing event. Here you will find activities, events, broadcasts, and resources from NASA and our partners across the nation.”