When each region is actually worth the trip
Pick a month below and see all four regions’ Maplequarry scores side by side — the same model behind the homepage instrument, without needing to switch regions one at a time.
Scores use the same darkness × regional visibility × sky-clarity model described on how it works. September is shown by default because it’s the equinox — both longer nights and a seasonal geomagnetic bump land at once.
The winter core: November through March
This five-month stretch is when all four regions post their strongest, most consistent scores. Nights are long enough everywhere that darkness stops being the limiting factor, which means the differences you see between regions in this window are mostly about geomagnetic positioning and sky clarity — Yellowknife and Churchill pull ahead, Whitehorse and Iqaluit trail a little but remain genuinely worthwhile.
Within that window, January is usually the coldest and darkest; late February and March trade a small amount of darkness for noticeably less brutal temperatures, plus the March equinox bump.
The equinox effect: September and March
Both equinoxes get a deliberate boost in the Maplequarry model, and it’s not decorative — geomagnetic activity has a well-documented seasonal pattern that peaks around the equinoxes (linked to the angle between Earth’s magnetic field and the solar wind), independent of the solar cycle’s multi-year swing. September also has the advantage of milder shoulder-season temperatures than deep winter, while still offering close to 12 hours of darkness across all four regions.
The dead zone: May through July
Don’t book an aurora trip to any of these four regions in this window. Yellowknife and Whitehorse sit close enough to the Arctic Circle that true darkness nearly vanishes at midsummer; Churchill and Iqaluit keep a thin sliver of dark sky but not enough to reliably work with. Whatever the Kp index is doing, there simply isn’t enough night to see it.
How many nights to actually budget
A single night is a coin flip against weather alone, even in a strong month. Yellowknife-area operators commonly cite a roughly 95% chance of at least one sighting across a three-night stay in peak season, and 80–90% across five nights even in the shoulder months of September and October when Kp reaches 1.0 or higher. Build slack into the itinerary rather than a single all-or-nothing night.