Gainesville to reach record-high temperatures during heat wave "While high temperatures are not uncommon in June and July, McGinnis said Gainesville has not had a high of 100 degrees since June 16, 2015. “Gainesville has hit 100 degrees in the month of May five times in the past 129 years,” he said." If it hits 100 tomorrow, which it very well could, that would make 4 times in a row this year alone. Thank gawd for AC, pools, lakes and springs. And Netflix.