Where in Oregon is best for the aurora?

By geomagnetic latitude, Gresham at 51.0°. No town sits at 60 degrees or more, so every town needs some activity.

Which town in Oregon has the longest December night?

Gresham, with 14.0 hours of civil night on December 15.

Which town in Oregon has the clearest dark season?

Salem, with 63% 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 Oregon?

September for 5 of 5 towns, by civil night times the clear share of the sky. Each town page gives its own month.

United States · 7 towns

Aurora towns in Oregon

Answer

Glow tracks 7 towns in Oregon, United States. They sit between 50.0° at Albany, Oregon and 51.0° at Gresham on the IGRF-14 dipole. The regional median, 50.9 degrees, is 0.6 degrees below the median for United States.

50.9°

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 Hillsboro and Salem, 0.6 degrees. 3 neighbouring pairs sit within 0.5 degrees of each other, close enough that the order between them means little.

Of the 5 indexed towns in Oregon, 5 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	Gresham	51.0°
2	Portland, Oregon	50.9°
3	Hillsboro	50.9°
4	Salem	50.3°
5	Albany, Oregon	50.0°

Ranked by December darkness

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

Civil night on December 15, longest first
Rank	Town	Value
1	Gresham	14.0 h
2	Portland, Oregon	14.0 h
3	Hillsboro	14.0 h
4	Salem	14.0 h
5	Albany, Oregon	14.0 h

Ranked by clear dark season

NASA POWER's 2001 to 2020 climatology puts median cloud amount in the dark months at 65%, against 61% nationally. Salem is clearest at 63% and Hillsboro cloudiest at 65%. 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	Salem	63%
2	Albany, Oregon	63%
3	Gresham	65%
4	Portland, Oregon	65%
5	Hillsboro	65%

Multiplying civil night by the clear share of the sky, September comes out best for 5 of the 5 towns. SWPC notes a tendency toward larger storms near the equinoxes, which this score does not include.

Every town

7 towns in Oregon
Town	Dipole	Storm needed	Dec 15 night	Dark-month cloud	Best month
Gresham	51.0°	G2 or more	14.0 h	65%	Sep
Portland, Oregon	50.9°	G2 or more	14.0 h	65%	Sep
Hillsboro	50.9°	G2 or more	14.0 h	65%	Sep
Beaverton *	50.9°	G2 or more	14.0 h	65%	Sep
Tigard *	50.8°	G2 or more	14.0 h	65%	Sep
Salem	50.3°	G2 or more	14.0 h	63%	Sep
Albany, Oregon	50.0°	G2 or more	14.0 h	63%	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 Oregon is best for the aurora?: By geomagnetic latitude, Gresham at 51.0°. No town sits at 60 degrees or more, so every town needs some activity.
Which town in Oregon has the longest December night?: Gresham, with 14.0 hours of civil night on December 15.
Which town in Oregon has the clearest dark season?: Salem, with 63% 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 Oregon?: September for 5 of 5 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.