G1minor
The geomagnetic storm of 13 December 1974
On 13 December 1974 the Kp index reached 5−: a G1 (minor) storm, with 6 hours at Kp 5 or more. At its peak the lights could be seen from 245,598 places in the atlas, down to about 52° magnetic latitude.
Kp 5−Peak Kp · 13 December 1974 15:00 UT
6Hours at Kp 5 or more
39Largest ap
Solar cycle 20Year 11 of solar cycle 20
Kp every three hours
56789
12 Dec13 Dec14 Dec
Where the lights could be seen
At Kp 5− the lights reach 245,598 places of the atlas on the horizon and 66,942 overhead, down to about 52° magnetic latitude.
Countries
Russia106,926 placesSweden27,845 placesFinland24,291 placesUnited States16,789 placesCanada16,015 placesNorway13,111 placesLithuania10,842 placesLatvia7,542 placesEstonia6,893 placesUnited Kingdom5,556 placesAt the edge: just within reach
MoscowRussiaTorontoCanadaNovosibirskRussiaChelyabinskRussiaOmskRussiaMississaugaCanadaCopenhagenDenmarkBramptonCanadaThe largest towns that could see them
MoscowRussia · 13.3MSaint PetersburgRussia · 5.65MTorontoCanada · 2.79MMontrealCanada · 1.9MNovosibirskRussia · 1.64MYekaterinburgRussia · 1.47MKazanRussia · 1.33MCalgaryCanada · 1.31MNizhny NovgorodRussia · 1.2MChelyabinskRussia · 1.18MOmskRussia · 1.1MKrasnoyarskRussia · 1.09MPermRussia · 1.03MOttawaCanada · 1.02MEdmontonCanada · 1.01MStockholmSweden · 985kTyumenRussia · 872kWinnipegCanada · 750kSeattleUnited States · 737kMississaugaCanada · 718kOsloNorway · 718kHelsinkiFinland · 694kGothenburgSweden · 675kCopenhagenDenmark · 667k