Solar cycle comparison
Is Solar Cycle 25 stronger or weaker than earlier cycles at the same stage? This tool lines up all 25 numbered solar cycles by the number of months since each one's minimum, so you can compare them at exactly the same point. Solar Cycle 25 began in December 2019; the latest month, October 2026, is 82 months after that minimum, with a monthly mean sunspot number of 45.7 (provisional).
Updated 2 November 2026. Source: WDC-SILSO, Royal Observatory of Belgium, with recent months as published by the NOAA Space Weather Prediction Center. Data hub: Sunspot and solar cycle data.
Compare one cycle with every other cycle
Over its first 83 months (December 2019 to October 2026), Solar Cycle 25 had an average monthly sunspot number of 85.7 (including provisional months). Of the 25 cycles with a value 82 months after their minimum, it ranks 18th, where 1st is the most active. The highest was Solar Cycle 19 (171.5, February 1961) and the lowest Solar Cycle 6 (32.2, May 1817). The average of the other 24 cycles at that point was 105.6, so Solar Cycle 25 was 18.8% below that average. Solar Cycle 24 at the same point (October 2015) had 66.8.
Compare two cycles head to head
Lined up by months since their minimum, Solar Cycle 25 (from December 2019) and Solar Cycle 24 (from December 2008) can be compared over the 83 months that Solar Cycle 25 has run so far. Over that time Solar Cycle 25 averaged 85.7 and Solar Cycle 24 66.8, so Solar Cycle 25 was 28.3% above Solar Cycle 24. Solar Cycle 25 had the higher monthly mean in 66 months and Solar Cycle 24 in 16 months (1 month level). Their highest 13-month smoothed values so far were 160.9 (October 2024, 58 months after the minimum) and 116.4 (April 2014, 64 months after the minimum). At month 82 after the minimum the monthly means were 45.7 (October 2026, provisional) and 63.6 (October 2015).
Key figures
- Over its first 83 months (December 2019 to October 2026), Solar Cycle 25 had an average monthly sunspot number of 85.7. That ranks 18th of the 25 numbered cycles over the same number of months, 18.8% below the average of the 24 earlier cycles (105.6). #
- Solar Cycle 24 averaged 66.8 over its first 83 months (December 2008 to October 2015). Month for month since their minimums, Solar Cycle 25 has had the higher monthly mean in 66 of those 83 months and Solar Cycle 24 in 16. #
- The monthly mean of 45.7 in October 2026 (provisional), 82 months after the Cycle 25 minimum, ranks 24th of 25 cycles at the same point. #
- The latest 13-month smoothed value, 88.6 for April 2026 (76 months after the minimum), ranks 20th of 25 cycles at the same point. #
- Over the same first 83 months, the most active cycle was Solar Cycle 19 (average 171.5, April 1954 to February 1961) and the least active Solar Cycle 6 (32.2, July 1810 to May 1817). #
- Solar Cycle 25's highest 13-month smoothed value so far, 160.9 in October 2024, came 58 months after its minimum. The 24 complete cycles took 4.4 years (52 months) on average to reach their smoothed maximum. #
Every solar cycle by months since its minimum
Every cycle 82 months after its minimum
The table lines each cycle up at the point Solar Cycle 25 has reached (October 2026). Rank is by the average monthly sunspot number since the minimum (1st = most active). Each cycle has its own link, for example #cycle-19.
| Cycle | Began (minimum) | Same point | Monthly mean | 13-month smoothed | Average since minimum | Rank |
|---|---|---|---|---|---|---|
| 25 | December 2019 | October 2026 | 45.7 | – | 85.7 | 18th |
| 24 | December 2008 | October 2015 | 63.6 | 64.3 | 66.8 | 22nd |
| 23 | August 1996 | June 2003 | 118.7 | 101.7 | 118.1 | 9th |
| 22 | September 1986 | July 1993 | 80.4 | 76.5 | 138.0 | 4th |
| 21 | March 1976 | January 1983 | 115.5 | 127.9 | 144.2 | 3rd |
| 20 | October 1964 | August 1971 | 87.0 | 91.5 | 106.6 | 14th |
| 19 | April 1954 | February 1961 | 65.4 | 105.9 | 171.5 | 1st |
| 18 | February 1944 | December 1950 | 76.7 | 102.4 | 136.2 | 6th |
| 17 | September 1933 | July 1940 | 112.5 | 112.6 | 114.8 | 12th |
| 16 | August 1923 | June 1930 | 48.0 | 65.2 | 87.0 | 17th |
| 15 | July 1913 | May 1920 | 55.4 | 64.4 | 92.0 | 16th |
| 14 | January 1902 | November 1908 | 75.9 | 86.5 | 71.3 | 21st |
| 13 | March 1890 | January 1897 | 67.6 | 55.0 | 93.3 | 15th |
| 12 | December 1878 | October 1885 | 64.5 | 78.7 | 78.8 | 19th |
| 11 | March 1867 | January 1874 | 101.4 | 86.3 | 130.9 | 8th |
| 10 | December 1855 | October 1862 | 79.8 | 111.3 | 110.0 | 13th |
| 9 | July 1843 | May 1850 | 117.0 | 135.7 | 117.7 | 10th |
| 8 | November 1833 | September 1840 | 123.3 | 89.1 | 137.6 | 5th |
| 7 | May 1823 | March 1830 | 141.0 | 108.3 | 63.0 | 23rd |
| 6 | July 1810 | May 1817 | 35.3 | 69.3 | 32.2 | 25th |
| 5 | April 1798 | February 1805 | 73.5 | 82.0 | 48.7 | 24th |
| 4 | September 1784 | July 1791 | 118.3 | 109.9 | 150.2 | 2nd |
| 3 | June 1775 | April 1782 | 68.3 | 70.0 | 135.9 | 7th |
| 2 | June 1766 | April 1773 | 54.8 | 67.3 | 115.7 | 11th |
| 1 | February 1755 | December 1761 | 76.7 | 119.6 | 72.7 | 20th |
Download the data
Every month of every solar cycle, by months since the minimum (CSV): cycle, months since minimum, calendar month, monthly mean, 13-month smoothed value, average since the minimum and a provisional flag. The sunspot numbers come from WDC-SILSO, Royal Observatory of Belgium, which distributes them under a CC BY-NC 4.0 licence (SILSO data policy). You may reuse the file for non-commercial purposes under the same licence, with credit to PolarisWire and WDC-SILSO, Royal Observatory of Belgium, and a link to this page.
Cite or link to this tool
Teachers, students, writers, radio amateurs and researchers are welcome to use and link to this comparison. Each key figure and cycle has its own link, such as #same-point-average or #cycle-24.
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How the comparison works
Monthly values are the monthly mean total sunspot number (version 2.0) from the World Data Center SILSO at the Royal Observatory of Belgium, Brussels, the same series used by the sunspot cycle lookup. Recent months use the same SILSO values as published by the NOAA Space Weather Prediction Center for the Solar Cycle 25 tracker; the most recent months are provisional and may be revised by SILSO.
Cycle start dates come from the SILSO table of solar cycle minima and maxima (CSV). Each cycle runs from the month of its smoothed minimum (month 0) to the month before the next cycle's minimum, and cycles are compared at the same number of months after their minimum. The 13-month smoothed value is SILSO's standard running mean centred on each month, with the first and last months at half weight, so the most recent six months have none yet. The average since the minimum is the mean of the monthly values from month 0 to the chosen month, rounded to one decimal. Ranks count only the cycles that have a value at that point, and 1st is the most active. This page is updated daily with the tracker's latest data.