Solar Cycle Progression

The observed and predicted ​Solar Cycle is depicted in Sunspot Number in the top graph and F10.7cm Radio Flux in the bottom graph.

An updated version of the Solar Cycle prediction product is now available on NOAA's Space Weather Prediction Testbed.

In both plots, the black line represents the monthly averaged data and the purple line represents a 13-month weighted, smoothed version of the monthly averaged data. The slider bars below each plot provide the ability to display the sunspot data back to solar cycle 1 and F10.7 data back to 2004.

The mean forecast for the current solar cycle (Cycle 25) is given by the red line. This is based on an international panel that was convened in 2019 for this purpose. In February, 2023 the plot was modified to show the full range of the 2019 Panel prediction as the gray shaded region (similarly for the F10.7 cm plot). This takes into account expected uncertainties in the cycle start time and amplitude. Use the drop-down menu below each plot to display specific curves within this range.

These plots, like many on the SWPC website, are interactive.

• Mousing your cursor over the plots will display the data values applicable to the date the cursor is over.

• Left clicking on the data and holding while you drag will define a zoom window.

• Use the buttons above each plot to return to the default zoom showing the current cycle or to show the entire available data set.

• There is also an option to toggle the solar cycle numbering on/off.

• Beneath each main plot window, the entire time series is shown and you can click/hold on either side of the blue shaded region to expand or contract the zoom window or if you click/hold on the blue shaded region itself, you can slide it to anywhere in the time series.

• A drop down menu above and to the right of each plot allows you to PRINT, or download PNG, PDF, or SVG format images of the associated plot

Solar cycle predictions are used by various agencies and many industry groups. The solar cycle is important for determining the lifetime of satellites in low-Earth orbit, as the drag on the satellites correlates with the solar cycle, especially as represented by F10.7cm. A higher solar maximum decreases satellite life and a lower solar maximum extends satellite life. Also, the prediction gives a rough idea of the frequency of space weather storms of all types, from radio blackouts to geomagnetic storms to radiation storms, so is used by many industries to gauge the expected impact of space weather in the coming years.