Solar cycle 2 was the second solar cycle since 1755, when extensive recording of sunspot activity began.^[1][2] The solar cycle lasted 9 years, beginning in June 1766 and ending in June 1775. The maximum smoothed sunspot number observed during the solar cycle was 193.0 (September 1769), and the starting minimum was 18.6.^[3]

Sunspot observations by Alexander Wilson during this period established the Wilson effect.

• List of solar cycles