Solar Cycle 25

| Charts

Sunspots fell to 60.3 in September 2026

The yearly mean of NOAA's monthly sunspot numbers climbed from 3.6 in 2019 to 154.5 in 2024, then fell to 123.5 in 2025. In September 2026 the monthly number was 60.3, the lowest of the last 12 months.

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Sunspots climbed for five years to a 2024 peak

Yearly means rose from a low of 3.6 in 2019 to 154.5 in 2024, the top of Solar Cycle 25 in these figures.

Yearly mean sunspot numberSunspots
201639.8 sunspots
201721.8 sunspots
20187 sunspots
20193.6 sunspots
20208.8 sunspots
202129.5 sunspots
202283 sunspots
2023125.3 sunspots
2024154.5 sunspots
2025123.5 sunspots

Source: NOAA SWPC

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Monthly sunspots fell to 60.3 in September

The monthly number has swung from month to month but trended down over the past year.

Monthly sunspot numberSunspots
Dec 25124.2 sunspots
Jan 26115 sunspots
Feb 2677.4 sunspots
Mar 2686.6 sunspots
Apr 2679.3 sunspots
May 26101.5 sunspots
Jun 2694.4 sunspots
Jul 2678.1 sunspots
Aug 2676 sunspots
Sep 2660.3 sunspots

Source: NOAA SWPC

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Solar radio flux dropped to 105.41 in September

The F10.7 radio flux, a second measure of solar activity, peaked at 160.13 in December 2025 within this year of data.

Monthly F10.7 radio fluxSolar flux units
Dec 25160.13
Jan 26151.16
Feb 26135.93
Mar 26130.66
Apr 26120.01
May 26125.69
Jun 26138.21
Jul 26136.01
Aug 26116.22
Sep 26105.41

Source: NOAA SWPC

Records behind the charts

  1. NOAA's observed solar cycle indicesNOAA SWPC | | Research
  2. Solar cycle progressionNOAA SWPC | | Research

Sources

Covers 7 October 2026; sources read up to Wednesday 7 October 2026, UTC.
How this page is made: a HiveBoss Bee gathers the agency's published tables, and every record links to its source.
The words were written by AI; check the original before relying on them.