Northern lights (aurora borealis) are happening high above Earth’s atmosphere almost every day, but how often you actually see them depends on darkness, location, weather, and solar activity.

How often they appear

  • Auroras occur year-round because the Sun’s charged particles are constantly interacting with Earth’s magnetic field.
  • They are only visible when the sky is dark enough, so in Arctic regions the practical “seeing season” typically runs from late August to around April.
  • In prime locations like Lapland, the lights can be visible on roughly every second clear night during the main season, which works out to about 200 nights per year in the far north.

Best time of year and night

  • Best months in many northern destinations: late September to March/early April, when nights are long and dark.
  • Within a given night, auroras can appear anytime it is dark, but they most often peak between about 9 pm and 2 am, with many of the brightest shows around 11 pm to midnight.

Why you might miss them

  • In summer at high latitudes, the “midnight sun” or very bright nights can completely hide the aurora even though it is still happening overhead.
  • Cloud cover is usually a bigger enemy than aurora activity itself; a region like northern Finland can have frequent auroras, but you will not see them through thick cloud.
  • Your odds improve a lot if you stay several nights in an aurora zone; for example, a three-night stay in peak season in Lapland can give roughly a three-in-four chance to catch at least one display in clear conditions.

TL;DR: The northern lights are active most nights near the polar regions, but for an observer on the ground they are typically visible about every other clear night in the main season, mostly between 9 pm and 2 am.

Information gathered from public forums or data available on the internet and portrayed here.