Solar cycles are nearly periodic 11-year changes in the Sun 's activity that are based on the number of sunspots present on the Sun's surface. The first solar cycle conventionally is said to have started in 1755. The source data are the revised International Sunspot Numbers (ISN v2.0), as available at SILSO. [1] .

The observed and predicted Solar Cycle is depicted in Sunspot Number in the top graph and F10.7cm Radio Flux in the bottom graph. The predicted progression for the current solar cycle (Cycle 25) is given by the magenta line, with associated uncertainties shown …

Historical solar cycles. The chart on this page shows the sunspot numbers since 1749. That's when the extensive recording of solar sunspot activity began. You can zoom in on this plot by selecting a time period that you wish to view.

The Solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surface.

3 days ago · Each month the solar prediction is updated using historical and the latest month’s observed solar indices to provide estimates for the balance of the current solar cycle and the next.

5 days ago · Graphs of Historical Solar Cycles. Press the down arrow to display the list of solar cycles. Click on the required solar cycle, then press the Display button.

4 days ago · The solar cycle is the cycle that the Sun’s magnetic field goes through approximately every 11 years. Our Sun is a huge ball of electrically-charged hot gas. This charged gas moves, generating a powerful magnetic field.

Mar 28, 2025 · These charts on this page resemble the progress of the solar cycle. The charts are updated every month by the SWPC with the latest ISES predictions. Observed values are initially temporary values that are replaced with the final data once it is available.

The total number of sunspots has long been known to vary with an approximately 11-year repetition known as the solar cycle. The peak of sunspot activity is known as solar maximum and the lull is known as solar minimum.

Wikimedia Commons has media related to Solar cycles. This category has only the following subcategory. The following 31 pages are in this category, out of 31 total. This list may not reflect recent changes.