Several magnetic observatories report and forecast geomagnetic activity responsible for producing the auroras occasionally seen in the skies over Door County. The Ottawa (OTT) Magnetic Observatory is the nearest station located within the same degrees of latitude as Door County. The Boulder Geomagnetic Observatory in Colorado is also relatively nearby, but it is located several degrees of latitude to the south.
Serious aurora-seeking tourists travel closer the poles; Door County is not a great place to look for auroras because it is too far south. Because of this, Door County is only considered part of the sub-auroral zone. Auroras in Door County can only be seen when the geomagnetic storms are particularly strong. Yet, if you are going to Door County anyway, why not look for auroras? And if you follow the forecasts and plan your travels around them, you might even witness a display of the sort photographed by members of the Auroras of Door County Facebook group.
Forecast resources
Forecast hourly ranges for Ottawa
Forecast classification chart for interpreting the results in the hourly ranges table (scroll down to Ottawa)
Current regional magnetic conditions for Eastern North America (from Space Weather Canada)
Magnetic summary plots – last 24 hours (from Space Weather Canada)
27 day magnetic activity forecast for Ottawa
Boulder Magnetometer
NOAA 30-minute forecast; this is also used for the left-hand panel at https://spaceweather.com/
If you are unfamiliar with the charts, How to read a solar forecast from the The Royal Canadian Geographical Society can be a good resource.
Links about the facilities in Ottawa and Boulder:
https://www.geomag.nrcan.gc.ca/obs/ott-en.php
https://www.usgs.gov/programs/geomagnetism/science/boulder-bou
A large list of geomagnetic observatories:
https://intermagnet.github.io/metadata/#/
Where to see auroras in Door County
Light pollution can obscure auroras. Light pollution is lower on the islands and in most places on the Lake Michigan side of the peninsula. And in the winter it may be possible to head out onto the ice. Great Lakes ice conditions are reported at https://www.glerl.noaa.gov/data/ice/ . If you are uncertain about light pollution, you can find the spot you have in mind on the astronaut photographs at https://en.wikipedia.org/wiki/File:ISS054-E-13520.jpg and https://en.wikipedia.org/wiki/File:ISS030-E-183973.jpg. If the area you have in mind is one of the bright spots, or is just south of one of the bright spots, you might want look for another location instead.
On the Door Peninsula
If you are visiting further north, Newport State Park at 475 County Rd NP is a good place to see auroras because the area has little light pollution and the park has shoreline facing to the north. Unless you are camping, the park closes at 11 PM.
Link:
https://dnr.wisconsin.gov/topic/parks/newport
Yet the Mud Lake Wildlife Management Area to the south of Newport State Park does not have a nighttime closing period. The entire shoreline of the lake is within the WMA, including the southern part which offers an excellent view of the northern sky. Visitors may find that access through the woods to the shore of the lake is easier in the dead of winter when things are more frozen.
Link:
https://dnr.wisconsin.gov/topic/Lands/WildlifeAreas/mudlk.html
And just to the east of Mud Lake, the Baileys Harbor Boreal Forest And Wetlands Wisconsin State Natural Area also has no closing hour for the night. The SNA includes some north-facing shore along Lake Michigan. As with Mud Lake, camping is not allowed.
Link:
https://dnr.wi.gov/topic/Lands/naturalareas/index.asp?SNA=284
If you are visiting further south, light pollution is lower near Bay Shore County Park along Highway 57, with an address of 5637 Sturgeon Bay Rd. (Sturgeon Bay Road is Highway 57.) The park has a webcam on Youtube, which you can use to check to see if the sky is cloudy before making the drive. Only registered campers are permitted in the park after 11:00 PM.
Links:
https://www.youtube.com/watch?v=RGoVwAcx990
https://www.browncountywi.gov/community/parks-department/general-information/bay-shore-park/
https://www.browncountywi.gov/community/parks-department/general-information/camping/
Aurora Bay is a small bay which is part of Green Bay. If you want to look for auroras at Aurora Bay, take Lime Kiln Road north, turning off of Lime Kiln to onto Boni’s Place. Boni’s Place dead ends at Aurora Bay. The road right-of-way as it meets the bay is a small water-access site open to the public. It has a good view of the northern sky.
If you are staying in Algoma or Sturgeon Bay, the Legacy Preserve at Clay Banks on 1188 South Lake Michigan Drive is not far away. The parking lot is a good place to look north for auroras, and the rocky beach at the bottom offers a good view of the northeast horizon. Because it is not a town, county, or state park, there is no nighttime closing time, although camping for the night is not permitted.
Links:
https://www.doorcountylandtrust.org/legacy-preserve-at-clay-banks/
http://map.co.door.wi.us/map/index.html?call=search_pin&fieldname0=PIN&value0=0060016262611
On Islands
If you are on Washington Island, the Little Lake Nature Preserve on 2285 Main Road has good views towards both the northeast and the northwest sky, depending on whether you decide to look out over Green Bay or over Little Lake.
Links:
https://www.doorcountylandtrust.org/little-lake-nature-preserve-3/
http://map.co.door.wi.us/map/index.html?call=search_pin&fieldname0=PIN&value0=0280223342931D
On Rock Island, campsites 23 through 29 are in proximity to good views of the northeast shore. As with Newport State Park, the park closes at 11 PM for non-campers, and the ferry’s hours of operation also restrict the park’s access for non-campers.
Links:
https://dnr.wisconsin.gov/topic/parks/rockisland
https://wisferry.com/rock-island
Although there is no ferry access to Detroit Island, the Detroit Harbor Nature Preserve includes some areas with north-facing shore. Similar to the Legacy Preserve at Clay Banks, it is not a town, county, or state park. As a result, there is no closing time for the night, although camping for the night is not permitted.
http://map.co.door.wi.us/map/index.html?call=search_pin&fieldname0=PIN&value0=0280113332912C (one of the tracts)
https://www.doorcountylandtrust.org/detroit-harbor-nature-preserve/ ( general information about the preserve, focused more on the Washington Island portion)
Another good place to look for auroras along Green Bay is on Chambers Island. Although there is no ferry access, there is a dock open to the public, and there are tracts of land open to public access which are enrolled in the Wisconsin Managed Forest Land program. Some tracts are along the northern shores of Mackaysee Lake and Green Bay. There is no nighttime closing time for lands enrolled in the Wisconsin Managed Forest Land program.
Links:
https://en.wikipedia.org/wiki/Chambers_Island#Public_and_private_areas
https://www.doorcountylandtrust.org/wp-content/uploads/2020/04/Chambers-Island-Hunting-Map-4-2020.pdf
https://dnrmaps.wi.gov/opfl/