Summer no longer starts on June 20, according to new research.According to a new survey of 3,250 Americans, 59% of respondents said their summer will be in full swing well before the "official" start of summer on the solstice (June 20).Many said the start of summer doesn't depend on the calendar date at all — 51% of respondents believe the season starts when the temperature hits 75 degrees.Other respondents think the start of summer depends more on specific activities taking place, with the top activity found to be buying ice cream from an ice cream truck (34%).Hosting or attending a barbeque (34%) and floating on a river (33%) rounded out the top three activities most likely to signify the start of summer.Conducted by OnePoll on behalf of Waterloo Sparkling Water, the survey also examined the other summer activities respondents are planning to include as they make summer 2021 bigger and better than last year.