G2 (Moderate) Geomagnetic Storm of December 10, 1982

Name: G2 (Moderate) Geomagnetic Storm of December 10, 1982
Start: 1982-12-10T06:00:00.000Z
End: 1982-12-10T18:00:00.000Z
Location: Earth

December 10, 1982 · 12 hours

A G2 (moderate) geomagnetic storm began December 10, 1982, reached Kp 6+ and lasted 12 hours, with a daily Ap as high as 46; at that Kp the aurora may be seen from about 53 degrees geomagnetic latitude.

The Kp through the storm

Began Dec 10, 06:00 UTC, peaked in the block from Dec 10, 06:00 UTC, ended Dec 10, 18:00 UTC.

From 00 UT the day before to the end of the day after. Blocks in the storm are colored by level; the rest are gray.

The storm

Peak Kp: 6+ (6.33)
NOAA level: G2 Moderate
Duration: 12 hours
Highest daily Ap: 46
Highest 3-hour ap: 94
Rank since 1932: 925 of 4,139

How far south the aurora could have been seen

At Kp 6+ NOAA’s scales put the aurora’s reach at about 53 degrees geomagnetic latitude: 45°N in the central US, 44°N in the eastern US, 48°N in the western US and 54°N in northern Europe.

NOAA says a G2 storm’s aurora has been seen as low as New York and Idaho.

US cities within reach, the southernmost first

Saint Paul, MN 53.5° geomag.
Minneapolis, MN 53.5° geomag.
Spokane, WA 53.7° geomag.
Anchorage, AK 61.9° geomag.

4 US cities of 150,000 people or more sit at or poleward of that line. Low on the northern horizon under a dark, clear sky; not a record of sightings.

Tonight’s aurora forecast

Day by day

The daily Ap is the mean of the day’s eight three-hour ap values.

UT day	Daily Ap	Highest Kp that day
December 10, 1982	46	6+

Flares before it

Peak (UTC)	Class	Region	Before the storm began
Dec 7, 23:54 UTC	X2.8	NOAA 4007	54 hours
Dec 9, 11:38 UTC	M9.2		18 hours
Dec 10, 04:32 UTC	M8.2	NOAA 4022	1 hour
Dec 8, 14:43 UTC	M6.7	NOAA 4022	39 hours
Dec 10, 02:48 UTC	M5.2	NOAA 4014	3 hours
Dec 6, 08:17 UTC	M2.9		94 hours

The strongest M and X class flares GOES recorded from four days before the storm began to its end, the window in which a coronal mass ejection launched with a flare usually arrives. A flare in this list is context, not proof of the cause: many storms come from coronal holes, and many flares launch nothing toward Earth.

The storm before, Dec 9 The storm after, Dec 17 Every storm of 1982 The strongest on record This day in weather history Tonight’s aurora forecast

Sources

Kp and ap from GFZ Helmholtz Centre for Geosciences, Geomagnetic Observatory Niemegk, licensed CC BY 4.0: Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., 2021, The geomagnetic Kp index and derived indices of geomagnetic activity, Space Weather, doi:10.1029/2020SW002641; data doi:10.5880/Kp.0001. Storms, levels and aurora reach worked out by WeatherOverTime from those values and NOAA’s space weather scales. Definitive through August 31, 2026; later values are preliminary. Rebuilt 2026-09-25. Flares from NOAA NCEI’s GOES X-ray flare reports (1975 to 2017) and SWPC’s edited solar event lists, public domain; classes as NOAA recorded them at the time.