G3strong

The geomagnetic storm of 5 – 6 October 1985

On 5 – 6 October 1985 the Kp index reached 7: a G3 (strong) storm, with 30 hours at Kp 5 or more. At its peak the lights could be seen from 512,587 places in the atlas, down to about 47° magnetic latitude.

Kp 7Peak Kp · 5 October 1985 18:00 UT

30Hours at Kp 5 or more

132Largest ap

Solar cycle 21Year 10 of solar cycle 21

Kp every three hours

56789

4 Oct5 Oct6 Oct7 Oct

Where the lights could be seen

At Kp 7 the lights reach 512,587 places of the atlas on the horizon and 227,980 overhead, down to about 47° magnetic latitude.

Countries

Russia167,389 placesUnited States77,563 placesPoland30,652 placesSweden27,876 placesGermany27,139 placesUnited Kingdom26,866 placesBelarus25,169 placesFinland24,291 placesLithuania20,495 placesCanada19,497 places

At the edge: just within reach

LondonUnited KingdomWashingtonUnited StatesRotterdamNetherlandsŁódźPolandDortmundGermanyBaltimoreUnited StatesEssenGermanyDuisburgGermany

The largest towns that could see them

Before and after

Previous storm27 September 1985 · Kp 5−

Next storm7 October 1985 · Kp 5

1985

Geomagnetic storms of 1985Every storm

Geomagnetic storms since 1932Geomagnetic storm archive

Strong storms at the same time of year

5 – 8 October 1960Kp 9 · 60 h

2 October 2013Kp 8− · 15 h

4 – 5 October 2000Kp 8− · 42 h

3 – 4 October 1937Kp 8− · 12 h

7 – 8 October 2015Kp 7+ · 39 h

3 – 4 October 2002Kp 7+ · 24 h