New Mexico's Whitewater Rafting Season starts in mid-April, as ski areas close down and the snow begins to melt. This is the beginning of the "High Water" rafting season. The early season until mid-June offers the biggest excitement and whitewater features. Increasing temperatures and declining water levels as summer progresses lead to New Mexico's technical late season runs. This is a great time for families to go rafting in New Mexico and lasts through the first week of September in most years.