We discuss the similarities and differences of two intervals of extreme interplanetary solar wind conditions, separated almost precisely by two solar cycles, in April 1979 and March–April 2001. The similarities extend to various data‐sets: Energetic particles, solar wind plasma and interplanetary magnetic field. In April 1979 observations were made by three spacecraft covering a wide longitudinal range (∼ 70°) in the heliosphere. Data are presented from Helios 2, located 28° East of the Sun‐Earth line at ∼ 2/3 AU, and from near the Earth. Observations of the 2001 interval are from Wind. We examine the geomagnetic activity during each interval. © 2003 American Institute of Physics