The solar minimum periods between Cycles18-19 thru Cycles 22-23 were only about 2 years long. But the minimum between Cycles 23-24 (the thick green line) was almost 5 years. And the current solar minimum (the thick red line) looks like it’s tracking another long solar minimum. The April 2020 data shows that the smoothed sunspot number decreased a bit more.

For the record, NOAA/NASA predicts that solar minimum will be in April 2020 plus or minus 6 months.

The first official Cycle 25 sunspot was in July 2019. We had more Cycle 25 sunspots in April 2020.. Hopefully more Cycle 25 sunspots will emerge to start increasing the smoothed sunspot number. Again, note that the smoothed sunspot number is 6 months behind the monthly mean sunspot numbers.

ARRL DX CW 2012 - Which 10M Path

Is the ionosphere really lower

Grand Solar Minima

Butterfly Diagrams and Solar Minimum

A Look at All Twenty Three Solar Cycles

The Robust Equatorial Ionosphere