01 Geomagnetic storms, 2026

After the Peak

The Sun's sunspots peaked in October 2024. The magnetic storms it throws at Earth have not faded since. 2025 had 239 three-hour periods of storm level or stronger, the most since 2003. 2026 has had 119 so far, including a Kp 9− storm on January 19. Each storm pushes the aurora's oval toward the equator.

Jan 19
  • Aurora, where the oval is
  • Pink tops, in strong storms
  • City outside the oval

Each frame is one three-hour Kp value from January 1 to October 29, 2026, played at 16 frames a second. The oval's size follows a standard rule of thumb and is approximate. Press pause or drag the slider to pick a moment.

02 Sunspots, cycles 17 to 25

A modest cycle, already past its peak

Sunspot numbers rise and fall over about eleven years. Cycle 25 began in December 2019 and peaked in October 2024 at a smoothed 159 sunspots, the seventh highest of the nine cycles since 1933. That is a third more than weak Cycle 24, and far short of Cycle 19's 287 in 1958. Monthly sunspots have since fallen from 216 in August 2024 to 60 in September 2026.

  • Cycles 17 to 24
  • Cycle 25

Thirteen-month smoothed monthly sunspot number, aligned at each cycle's minimum. The last six months of Cycle 25 can't be smoothed yet and are drawn as raw monthly values. Hover or tap to read a month.

03 Strongest Kp each day, 1932 to 2026

Storms cluster after the peak

Each row is a year and each sliver a day, brighter when the day's Kp was higher. Quiet years are nearly dark. Of the ten busiest storm years since 1932, nine came one to six years after a sunspot peak. Only 1947 was a peak year. The bars at right show each year's sunspots, and the bright rows trail them.

  • Kp 0 to 9
  • Sunspots that year

Storm level starts at Kp 5, the "G1" minor storm. Hover or tap to read a day.

04 Storm-level periods by month, aligned at each peak

Most storms come after the peak

In Cycles 17 to 24, 56% to 85% of storm-level periods came after the sunspot peak. Researchers link this to fast streams of solar wind from holes in the Sun's atmosphere, which are more common as a cycle declines. Cycle 25 is 23 months past its peak and at 51%. It has already had 36 periods at Kp 8− or higher, three times Cycle 24's 12 for its whole length.

  • Months before the peak
  • Months after it
  • Cycle 25

Each bar is one month's count of three-hour periods with Kp of 5− or higher. The percentage is the share of the cycle's storm-level periods after its peak. Cycle 25 isn't over, so its share will move. Hover or tap to read a month.

05 The ten strongest storm days since 1932

The biggest storms are rare

Ranked by the day's Ap, the average disturbance across all eight Kp readings, the strongest day since 1932 is November 13, 1960. May 11, 2024 is second, ahead of the March 1989 storm that blacked out Quebec. Aurora from it was reported as far south as Florida and Mexico. Seven of the ten came after their cycle's sunspot peak. May 2024 came five months before it.

  • After the cycle's sunspot peak
  • Before it
  • May 2024

Days within three days of a stronger storm are folded into it, so each bar is one storm. Ap is a daily index, so a short, intense storm can rank below a long one.

06 Method

How the numbers were built

Data

The Kp index is the planetary measure of magnetic disturbance, reported every three hours since 1932 on a scale of 0 to 9, with thirds (5−, 5, 5+). The Ap index averages a day's eight readings. Both come from GFZ Potsdam, downloaded October 30, 2026. Its latest day is October 29. Sunspot numbers are the monthly total from SILSO, to September 2026.

A storm-level period is one three-hour period with Kp of 5− or higher, the lower edge of NOAA's G1 minor storm level. Kp 8− marks the lower edge of its G4 severe level.

Each cycle runs from its smoothed minimum to the next. Its peak is the month of highest 13-month smoothed sunspot number. The cycle minima are found within a year of the dates in SILSO's cycle list.

The map places the oval's equatorward edge at about 66° of geomagnetic latitude at Kp 0, moving 2° toward the equator for each Kp step to about 48° at Kp 9. It places the geomagnetic pole at 80.7°N, 72.7°W.

Limits

  • Kp for recent months is preliminary and can change a little when it becomes definitive.
  • The map's oval is a simplified circle. The real one is lopsided and shifts through the day, and in extreme storms like May 2024 aurora was seen farther south than the rule gives.
  • Kp is capped at 9, so the strongest storms can't be told apart. Ap helps for whole days.
  • Storms need the Sun's eruptions or wind to point at Earth. Sunspot numbers only measure how active the Sun is overall.

Sources

  • Matzka and others, The geomagnetic Kp index and derived indices of geomagnetic activity, GFZ Potsdam, 2021. kp.gfz.de
  • SILSO, Royal Observatory of Belgium, Brussels: monthly sunspot number. sidc.be/SILSO
  • NOAA Space Weather Prediction Center, space weather scales. swpc.noaa.gov
  • Coastlines from Natural Earth, via world-atlas. naturalearthdata.com