What Kp is a G2 storm?

Kp = 6, on the NOAA Space Weather Scales. SWPC's oval-edge rule puts the average edge of the oval at 54 degrees geomagnetic at Kp 6.

How many G2 storms happen per year?

SWPC lists 600 per 11-year cycle on 360 days, about 33 storm days a year on average.

Which Glow towns does a G2 storm reach?

6 of 10 sit at or poleward of the Kp 6 oval edge: Reykjavik, Yellowknife, Tromsø, Fairbanks, Anchorage, Duluth.

Where has G2 aurora been seen?

NOAA's scale says: "aurora has been seen as low as New York and Idaho (typically 55° geomagnetic lat.)". Aurora is often seen hundreds of kilometers equatorward of where it actually sits, per SWPC.

Can I see a G2 storm from Minneapolis?

Possibly, low to the north. Minneapolis sits about 1.5 degrees south of SWPC's typical G2 latitude of 55 degrees, well inside the 1000 km viewing range.

NOAA G-scale · Kp = 6

G2 moderate geomagnetic storm and the aurora

Answer

G2 Moderate is Kp = 6 on NOAA's scale. At this level, SWPC says, "aurora has been seen as low as New York and Idaho (typically 55° geomagnetic lat.)". It occurs about 600 times per 11-year cycle.

Moderate, Kp = 6

NOAA Space Weather Scales

What SWPC says about G2

G2 matches Kp 6 on NOAA's scale. SWPC's tips page puts Kp 6 to 7 in the band where the aurora becomes quite bright and active, and says it might be possible to see it from the northern edge of the United States.

"aurora has been seen as low as New York and Idaho (typically 55° geomagnetic lat.)"
NOAA Space Weather Scales, G2 Moderate

The scale lists G2 aurora as seen as low as New York and Idaho, typically 55 degrees geomagnetic. Among Glow's lower 48 towns only Duluth sits above that line. The oval-edge rule puts the Kp 6 edge at 54 degrees, which also reaches Duluth.

G2 is the first level where the scale names a typical geomagnetic latitude, 55 degrees, and that line runs just south of Duluth. SWPC averages 360 G2 storm days per 11-year cycle, about 33 a year, so a G2 night is not rare. The open question is timing. A storm that peaks during your afternoon may have faded by nightfall, which is why the live oval map matters more than the level once the night begins.

"It should be noted that the aurora can often be observed hundreds of kilometers (miles) equatorward of the actual aurora so these figures do not indicate where the aurora may be but rather the point from which it may be observed."
NOAA SWPC, Tips on viewing the aurora

The 10 Glow towns at G2

6 of the 10 Glow towns sit at or poleward of SWPC's typical G2 latitude of 55 degrees. The Kp 6 edge at 54 degrees reaches 6 of them, and 10 sit within SWPC's 1000 km viewing distance of it. Minneapolis sits closest to that edge, 56 km south of it.

Each Glow town against the G2 typical latitude and the Kp 6 oval edge (54 degrees)
Town	Dipole	vs typical latitude	Kp 6 edge
Reykjavik	68.8°	+13.8°	Reaches the town
Yellowknife	68.5°	+13.5°	Reaches the town
Tromsø	67.5°	+12.5°	Reaches the town
Fairbanks	65.7°	+10.7°	Reaches the town
Anchorage	61.9°	+6.9°	Reaches the town
Duluth	55.4°	+0.4°	Reaches the town
Minneapolis	53.5°	-1.5°	56 km north
Seattle	53.0°	-2.0°	107 km north
Portland, Maine	52.9°	-2.1°	127 km north
Buffalo	52.0°	-3.0°	219 km north

Dipole latitude from IGRF-14. Typical latitude from the NOAA scale; positive means poleward of it. Edge from SWPC's 66 minus 2 per Kp rule, at 111.2 km per degree. All approximate.

How often G2 storms happen

SWPC lists 600 G2 storms per 11-year solar cycle, falling on 360 days. Spread evenly over the cycle, that is about 55 storms and 33 storm days a year. That is 2.8 times as many storm days as G3, the next level up.

NOAA G-scale average frequency, per 11-year cycle and per year
Level	Kp	Storms per cycle	Days per cycle	Days per year
G1 Minor	Kp = 5	1,700	900	82
G2 Moderate	Kp = 6	600	360	33
G3 Strong	Kp = 7	200	130	12
G4 Severe	Kp = 8, including a 9-	100	60	5.5
G5 Extreme	Kp = 9	4	4	0.4

Per-cycle counts from the NOAA scales page, where 1 cycle is 11 years. Per year: days per cycle divided by 11. Real storms are not spread evenly.

On a G2 night

Duluth and the Upper Midwest are in range. Get away from city light and face north.
Minneapolis, Seattle, Buffalo and Portland, Maine sit 1.5 to 3 degrees south of the G2 line; bright aurora 1000 km away can still clear the horizon.
Check NWS cloud for your spot and a backup site before driving.
In the far north, a G2 pushes the oval south of the usual position; look south as well as overhead if the live map shows the edge below your latitude.

Questions

What Kp is a G2 storm?: Kp = 6, on the NOAA Space Weather Scales. SWPC's oval-edge rule puts the average edge of the oval at 54 degrees geomagnetic at Kp 6.
How many G2 storms happen per year?: SWPC lists 600 per 11-year cycle on 360 days, about 33 storm days a year on average.
Which Glow towns does a G2 storm reach?: 6 of 10 sit at or poleward of the Kp 6 oval edge: Reykjavik, Yellowknife, Tromsø, Fairbanks, Anchorage, Duluth.
Where has G2 aurora been seen?: NOAA's scale says: "aurora has been seen as low as New York and Idaho (typically 55° geomagnetic lat.)". Aurora is often seen hundreds of kilometers equatorward of where it actually sits, per SWPC.
Can I see a G2 storm from Minneapolis?: Possibly, low to the north. Minneapolis sits about 1.5 degrees south of SWPC's typical G2 latitude of 55 degrees, well inside the 1000 km viewing range.

Sources and verification

NOAA Space Weather Scaleshttps://www.spaceweather.gov/noaa-scales-explanation
NOAA SWPC, Tips on viewing the aurorahttps://www.spaceweather.gov/content/tips-viewing-aurora
NOAA SWPC, Planetary K-indexhttps://www.swpc.noaa.gov/products/planetary-k-index

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.