Where in Wisconsin is best for the aurora?

By geomagnetic latitude, Eau Claire at 53.4°. No town sits at 60 degrees or more, so every town needs some activity.

Which town in Wisconsin has the longest December night?

Eau Claire, with 14.0 hours of civil night on December 15.

Which town in Wisconsin has the clearest dark season?

Janesville, with 59% mean cloud amount in the months with at least 4 hours of civil night (NASA POWER, 2001 to 2020).

What is the best month for aurora in Wisconsin?

September for 11 of 11 towns, by civil night times the clear share of the sky. Each town page gives its own month.

United States · 14 towns

Aurora towns in Wisconsin

Answer

Glow tracks 14 towns in Wisconsin, United States. They sit between 51.4° at Kenosha and 53.4° at Eau Claire on the IGRF-14 dipole. The regional median, 51.9 degrees, is 0.4 degrees above the median for United States.

51.9°

median geomagnetic latitude

IGRF-14 dipole, SunCalc, NASA POWER

Where the towns sit

60° geomagnetic or more, no storm needed55° to 60°, G1 or lessbelow 55°, storm needed

The widest gap in the dipole ranking falls between La Crosse and Milwaukee, 0.6 degrees. 9 neighbouring pairs sit within 0.5 degrees of each other, close enough that the order between them means little.

Of the 11 indexed towns in Wisconsin, 11 sit below 55 degrees and need a G2 or stronger storm by NOAA's typical latitudes.

Ranked by geomagnetic latitude

Dipole latitude, highest first
Rank	Town	Value
1	Eau Claire	53.4°
2	Green Bay	53.3°
3	Appleton	53.1°
4	Oshkosh	52.8°
5	La Crosse	52.4°
6	Milwaukee	51.9°
7	Waukesha	51.8°
8	Madison	51.8°
9	Racine	51.6°
10	Janesville	51.5°
11	Kenosha	51.4°

Ranked by December darkness

On December 15 the median town gets 13.8 hours of civil night, against 13.8 nationally. Eau Claire has the most at 14.0 hours and Milwaukee the least at 13.8. Every town keeps some civil darkness through the June solstice.

Civil night on December 15, longest first
Rank	Town	Value
1	Eau Claire	14.0 h
2	Green Bay	14.0 h
3	Appleton	13.9 h
4	Oshkosh	13.9 h
5	La Crosse	13.9 h
6	Milwaukee	13.8 h
7	Waukesha	13.8 h
8	Madison	13.8 h
9	Racine	13.8 h
10	Janesville	13.8 h
11	Kenosha	13.8 h

Ranked by clear dark season

NASA POWER's 2001 to 2020 climatology puts median cloud amount in the dark months at 61%, against 61% nationally. Janesville is clearest at 59% and Kenosha cloudiest at 74%. These are all-hours averages for 1 degree cells, not forecasts.

Mean cloud amount in months with 4 hours or more of civil night, clearest first
Rank	Town	Value
1	Janesville	59%
2	Eau Claire	60%
3	La Crosse	60%
4	Madison	60%
5	Waukesha	61%
6	Green Bay	61%
7	Appleton	61%
8	Oshkosh	61%
9	Milwaukee	71%
10	Racine	74%
11	Kenosha	74%

Multiplying civil night by the clear share of the sky, September comes out best for 11 of the 11 towns. SWPC notes a tendency toward larger storms near the equinoxes, which this score does not include.

Every town

14 towns in Wisconsin
Town	Dipole	Storm needed	Dec 15 night	Dark-month cloud	Best month
Superior *	55.3°	G1 or less	14.2 h	61%	Feb
Eau Claire	53.4°	G2 or more	14.0 h	60%	Sep
Green Bay	53.3°	G2 or more	14.0 h	61%	Sep
Appleton	53.1°	G2 or more	13.9 h	61%	Sep
Oshkosh	52.8°	G2 or more	13.9 h	61%	Sep
North La Crosse *	52.5°	G2 or more	13.9 h	60%	Sep
La Crosse	52.4°	G2 or more	13.9 h	60%	Sep
Milwaukee	51.9°	G2 or more	13.8 h	71%	Sep
West Allis *	51.8°	G2 or more	13.8 h	61%	Sep
Waukesha	51.8°	G2 or more	13.8 h	61%	Sep
Madison	51.8°	G2 or more	13.8 h	60%	Sep
Racine	51.6°	G2 or more	13.8 h	74%	Sep
Janesville	51.5°	G2 or more	13.8 h	59%	Sep
Kenosha	51.4°	G2 or more	13.8 h	74%	Sep

* Within 15 km of a larger town with the same rounded figures; its page points to that town. Cloud: NASA POWER mean for months with at least 4 hours of civil night.

Questions

Where in Wisconsin is best for the aurora?: By geomagnetic latitude, Eau Claire at 53.4°. No town sits at 60 degrees or more, so every town needs some activity.
Which town in Wisconsin has the longest December night?: Eau Claire, with 14.0 hours of civil night on December 15.
Which town in Wisconsin has the clearest dark season?: Janesville, with 59% mean cloud amount in the months with at least 4 hours of civil night (NASA POWER, 2001 to 2020).
What is the best month for aurora in Wisconsin?: September for 11 of 11 towns, by civil night times the clear share of the sky. Each town page gives its own month.

Sources and verification

GeoNames dump (CC BY 4.0)https://download.geonames.org/export/dump/
IGRF-14, NOAA NCEIhttps://www.ngdc.noaa.gov/IAGA/vmod/coeffs/igrf14coeffs.txt
NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/

Quoted figures last checked against their sources on 2026-09-30; next review 2026-12-31. Computed figures come from SunCalc and the IGRF-14 dipole as described in the methodology. Every quote is listed in the sources ledger.