The Solar Cycle: What 11 Years of Sunspots Means for Aurora Chasers
Some years, it feels like the Aurora is putting on a show every other week. Other years, even dedicated chasers go quiet for months. That's not bad luck: it's the sun running on an 11-year rhythm called the solar cycle, and knowing where that cycle stands right now is one of the most useful pieces of context for planning a trip.
What the solar cycle is
The sun's magnetic field flips polarity on a roughly 11-year rhythm, and as it does, the number of sunspots (dark, magnetically intense regions on the sun's surface) rises and falls in step. Sunspots are the source of the solar flares and coronal mass ejections (CMEs) that eventually reach Earth and drive geomagnetic storms, so more sunspots generally means more raw material for Aurora.
The cycle was first identified by German astronomer Heinrich Schwabe in 1843, after 17 years of tracking sunspots. Scientists have numbered every cycle since systematic records began in 1755, and we're currently in Solar Cycle 25.
Solar minimum vs. solar maximum
At solar minimum, sunspots are scarce or absent, flares and CMEs are infrequent, and geomagnetic storms are rare: Aurora activity retreats to a smaller, more reliable core of high-latitude locations like Tromsø, Yellowknife, and Fairbanks, which sit under the oval regardless. At solar maximum, sunspot number surges, flares and CMEs become frequent, and strong storms capable of pushing the Aurora to mid-latitudes happen many times a year.
Where we are now: Solar Cycle 25
Solar Cycle 25 officially began in December 2019 and ramped up faster and stronger than the original NASA/NOAA prediction panel forecast. Instead of the weak cycle originally expected, it turned out to be one of the more active cycles in decades, with solar maximum arriving around 2024–2025 and producing the strongest geomagnetic storm in over twenty years, the G5 event of May 2024.
| Cycle | Started | Solar max | Notable for |
|---|---|---|---|
| 24 | ~2008 | ~2014 | A notably weak cycle |
| 25 | Dec 2019 | ~2024–25 | Stronger than forecast; May 2024 G5 storm |
| 26 | ~2030 (est.) | ~2035–36 (est.) | Not yet begun |
As of 2026, Cycle 25 is past its peak and on the declining side, but that decline plays out gradually over several years, not months. Storm-level activity is still meaningfully elevated compared to the minimum years, so the next few seasons remain some of the better ones for Aurora chasing before things quiet down toward the later 2020s.
Does solar maximum guarantee Aurora?
No. Solar cycle sets the odds over a season, not the outcome on any single night. A solar-maximum year still needs a clear sky, real darkness, and a favourable Bz on the night you're actually out (see our five-factor guide). What it changes is the base rate: far more nights across a season will have the geomagnetic activity in place to begin with.
What this means for planning your trip
- Don't wait for "the perfect cycle": even solar minimum years produce plenty of Aurora at oval locations.
- The next several years are still favourable, as Cycle 25's decline from its 2024–25 peak is gradual.
- Stack the solar cycle with the equinox effect and a new moon for your best realistic odds on any given trip.
- If you're at a fringe, mid-latitude location, solar cycle timing matters far more to you than it does for someone already under the oval.