Hello,

The aurora take place in rings around the Earth's magnetic poles called the auroral ovals. For low geomagnetic activity levels, the southernmost or equatorward boundary of the auroral oval is about 66 degrees magnetic latitude. As activity levels increase, this boundary moves further south. For moderate activity levels, the equatorward boundary is at about 58 to 60 degrees latitude. For more extreme activity, the boundary can move south to 48 degrees.

You can see maps of the equatorward boundary of the auroral oval for different activity levels here:

http://www.swpc.noaa.gov/Aurora/index.html

The maps on this web page use a geomagnetic index called Kp to characterize geomagnetic activity levels. A Kp value of 0 means low activity and a Kp of 9 means high activity. There is actually a slight equatorward dip in the average geographic locations of the auroral oval over the midwest. If you live in Minnesota, you might be able to see aurora for moderate activity levels with Kp of 5.

Kris