The city of Phoenix reached its 31st consecutive day with at least 110-degree heat Sunday, rounding out what many scientists believe will be the Earth’s hottest month on record. Forecasters predict the arrival of thunderstorms late Monday likely will break the record heat on the last day of July; the expected high temperature in the Arizona capital July 31 is 106 degrees, according to the National Weather Service. The previous record for longest 110-degree streak in Phoenix was set in 1974, when it had 18 straight days of heat at or above 110 degrees.