Testing for Change in the Frequency of El Niño Events Academic Article uri icon


  • This note describes and applies a test for trend in the frequency of El Nino events over the period 1525-1987. Although there appears to have been a significant increase in frequency over this period, this result is consistent with an overall increase in the completeness of the historical record. When the analysis is repeated for the later part of the period and for strong events alone, no significant trends are found.

publication date

  • October 1995