Ten-year-old Nicholas Moreno (right) and his sister Maya, 13, throw buckets of water at each other as their 4-year-old brother Jacob watches in the shallows of the Merrimack River on Tuesday, accessed from the Sewall’s Falls Recreation Area in Concord. Their father can be seen paddling a small raft in the background.
Ten-year-old Nicholas Moreno (right) and his sister Maya, 13, throw buckets of water at each other as their 4-year-old brother Jacob watches in the shallows of the Merrimack River on Tuesday, accessed from the Sewall’s Falls Recreation Area in Concord. Their father can be seen paddling a small raft in the background. Credit: ELIZABETH FRANTZ / Monitor staff

Monday was the hottest June 12 in Concord’s recorded history, according to the National Weather Service. The 97-degree high broke the previous record of 94 set in 1973.

The two-day heatwave that prompted air conditioner installations throughout New England came right on the heels of one of the chilliest early June days in history.

The 50-degree high recorded in Concord on June 6 was the lowest maximum temperature for that date in the weather service’s records, which go back to the 1800s. Record low maximums were also set or tied in Worcester and Boston, Mass., and in Hartford, Conn., that day.

Monday’s heat similarly stretched as far north as Augusta, Maine, which set a high temperature record for the second day in a row and dismissed elementary schools early because of the heat, according to the Associated Press.

The 91-degree high in Augusta broke the 88-degree record from 1996, and on Sunday, the 91-degree high tied a 1984 record.

Burlington, Vt., also had two days of record heat with 95 degrees on Sunday and 94 on Monday.

(Nick Reid can be reached at 369-3325, nreid@cmonitor.com or on Twitter at @NickBReid.)