Solar cycle 13

Solar cycle 13 was the thirteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 11.9 years, beginning in March 1890 and ending in February 1902. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 87.9 (January 1894), and the minimum was 2.7. There were a total of approximately 938 days with no sunspots during this cycle.

There were a number of intense solar proton events during solar cycle 13. For example, a geomagnetic storm in September 1898 affected telegraph lines.