From the study, lani yo that ever occurred in the past, scientists found that in the winter and the summer of the northern hemisphere (during the month of December – February, June – August)
From the El Nino that has happened in the past, scientists have found that in the winter and summer of the Northern Hemisphere. (During December - February and June - August).
The El Nino that happened in the past scientists found that in winter and summer of the northern hemisphere (between December - February. And June - August).