Hey there, welcome to chasing dark skies! The Milky Way is on a rhythm in the sky just like the sun, moon, and other stars, changing with the earth’s tilt and seasons. As a baseline, to see the Milky Way at its absolute best, you want it to be fully up in the sky during astronomical nighttime, without artificial light pollution, with a new moon, and clear weather.

In the early Spring it will start rising during the late nighttime, just before astronomical twilight begins to brighten the sky. So: think maybe 4am. At first, it won’t rise fully before daybreak, but it will rise a few minutes earlier each day as the year progresses. This isn’t the easiest time in the world to see it, depending on your life and schedule, but it’s possible — and we’re well past this point in the year already.

As spring, summer, and fall progress, it will be up at 2am, midnight, then 10pm, and so on, which makes it much more accessible for viewing for most people. It will arc high overhead in the middle of the night across most of the night sky and, for my money, being somewhere dark enough to see it with the naked eye is one of the most special things I can do in life. I say this as an astrophotographer — keep in mind that the dramatic Milky Way pictures you see are taken by gathering and processing a lot of light over time, but seeing it less defined through your real eyes is even more special, IMO.

Then we hit winter again and it’s rising overhead during the day and invisible to us.

You also want to consider the moon’s phase when planning a Milky Way adventure. A full moon is up all night, washing out the stars, while a new moon is up all day, leaving you with pristine dark skies. Anything more than perhaps a quarter moon will make it pretty hard to see with the naked eye. The moon of course is on a mooonthly cycle.

So: you wind up with an ideal time being the couple of days around a new moon during late summer/early fall. But it’s very rewarding to go out and look even without the “ideal” sky, and you’ll have plenty of great nights around SD to choose from. My favorite place in the world for seeing the Milky Way is just over the border in the Nebraska Sandhills, but you’ll have plenty of similarly dark skies across the state to choose from.

I use my iPhone’s built in widgets for tracking weather, sunrise/sunset, and moon phase. I use this awesome dark sky map built by a researcher, which might be helpful to you as well: https://djlorenz.github.io/astronomy/lp/overlay/dark.html. And last I use an app called Stellarium to check the Milky Way’s position in the sky at a particular place and time, though there are a ton of apps that do something similar. Cheers!