This page features our predictions and forecasts for the Sun. Currently, we have Solar Cycle predictions
for Solar Cycle 24 (cycle amplitude and F10.7 flux) and
Solar Cycle 25 (cycle amplitude). We also show our predictions for the
evolution of the Sun's polar magnetic fields for the remainder of
Solar Cycle 24, which were used to predict the amplitude of Cycle 25.
Discover the Cycle 24 Predictions!
Predicting the behavior of a sunspot cycle is fairly reliable once the cycle is well underway. Former
MSFC Solar Physics Branch members Wilson, Hathaway, and Reichmann have studied the sunspot record for
characteristic behavior that might help in predicting future sunspot activity. Among the
most reliable techniques are those that use the measurements of changes in the Earth's magnetic
field at, and before, sunspot minimum, e.g. "geomagnetic precursors". This prediction was created using
a combination of geomagnetic precursors techniques. Details can be found here.
The prediction for Sunspot Cycle 24 gave a smoothed sunspot number V2.0 maximum of about 101
in late 2013. The smoothed sunspot number V2.0 reached a peak of 116.4 in April 2014. This will probably
become the official maximum. This second peak surpassed the level of the first peak (98.3 in March 2012).
Many cycles are double peaked but this is the first in which the second peak in sunspot number was larger
than the first. We are currently over nearing the end of Cycle 24. The predicted and observed size
makes this the smallest sunspot cycle since Cycle 14, which had a maximum smoothed sunspot number V2.0
of 107.2 in February of 1906.
We predict that Cycle 25 will be another small cycle, with an amplitude slightly smaller than (~95-97%)
the size of Cycle 24. Weak cycles such as this are preceded by long extended minima and we expect a similar
deep, extended minimum for the Cycle 24/25 minimum in 2020. Based on this solar cycle 25 prediction, we
expect that coming minimum last through the end of 2020 or beginning of 2021. Similarly, we expect that
the Cycle 24/25 minimum will include extended periods of spotless days throughout 2020 and into 2021.
Details about this predictions can be found in
Another indicator of the level of solar activity is the flux of radio emission from the Sun at a wavelength of 10.7 cm
(2.8 GHz frequency). This flux has been measured daily since 1947. It is an important indicator of solar activity
because it tends to follow the changes in the solar ultraviolet that influence the Earth's upper atmosphere and ionosphere.
Many models of the upper atmosphere use the 10.7 cm flux (F10.7) as input to determine atmospheric densities and satellite
drag. F10.7 has been shown to follow the sunspot number quite closely and similar prediction techniques can be used. Our
predictions for F10.7 are available in a text file, as a
Jpeg image, and as a pdf-file.
Current values for F10.7 can be
Discover the Cycle 24 Polar Field Predictions!
We have used our AFT code to predict the amplitude and hemispheric
asymmetry of the Sun’s polar magnetic fields at the start
of 2020, approximately the next cycle minimum. (Recall that observations have shown that
the strength of the polar fields is a good indicator of the strength of the next cycle.)
While we do not know the details of the active region sources and transport flows that
will occur between now and then, we use knowledgeable estimates, along with their known
variability, to produce a series of 32 realizations for the evolution of the Sun’s surface
magnetic field from the end of January 2016 to the start of January 2020. More information
about these predictions can be found in
In 2019 we updated our simulations with the through the beginning of 2019 and repeated our simulations.
More information about these updated predictions can be found in
Discover the Cycle 25 Predictions!
We find that the average strength of the polar fields near the end of Cycle 24 will be
similar to (or slightly weaker) that measured near the end of Cycle 23, indicating that
Cycle 25 will be similar in strength (or slightly weaker) to the current cycle. After
four years of simulation the variability across our ensemble indicates that the accumulated
uncertainty is on the order of about 15%. This uncertainty arises from stochastic variations
in the convective motion details, the active region tilt, and changes in the meridional flow.
In addition, small cycles (like cycle 24) are typically preceded by long extended minima, and
so we expect a similar long extended minimum before Cycle 25. More information about this prediction can be found in
More information about this prediction can be found in