The temperature in Boston reached 98 degrees Wednesday, a record high for the date, but that was only one data point in what is shaping up to be the hottest August recorded in the city’s history.
There is still one more day left in August, so any potential temperature records remain up in the air, National Weather Service meteorologists warned, but as of Thursday, the overall average temperature for Boston in August was the highest ever recorded, at 77.6 degrees.
The second-warmest was in 2016, when the overall average temperature was 76.4 degrees, according to weather service records.
The service began recording temperatures in Boston in 1872, meteorologist Benjamin Sipprell said.
The mercury climbed to 92 degrees on Thursday afternoon, Bill Simpson, another meteorologist with the service, said.
The city has been suffering a four-day heat wave. A total of 10 days this month so far have had high temperatures of 90 or more, according to NWS data.
The month’s average temperatures have been boosted not only by hot days but by a record spate of warm nights, which often haven’t provided much of a cooldown.
The Boston record for the most August days with a minimum temperature of 70 degrees or higher has already been set this month, at 15 days. The previous record was 14 days, set in 1988, according to weather service records.
That figure is not expected to increase in the last two days of the month. With a cold front moving through the region Thursday and Friday, the low temperatures in Boston are expected to dip into the 60s before midnight Thursday.
But don’t get too comfortable. After several cool days, the heat could return on Labor Day.
The 2018 summer as a whole has seen 29 days with a minimum temperature of 70 degrees or higher, which is also a record for Boston. The 29 days is near the record of 30 for a whole year; that record could also be tied or exceeded as soon as next week.
Thursday marked the 66th consecutive day with a minimum temperature of at least 60 degrees. The all-time record was set in 2010, when there were 80 consecutive such days, according to NWS records. It will take a few weeks to tell whether that record is broken.
Wednesday’s minimum temperature of 81 degrees was the second-highest low temperature ever recorded in Boston. The highest was 83 degrees on Aug. 2, 1975.
“Not sure whether to cheer this record, but yesterday #Boston recorded its 2nd warmest low temperature since records began in 1872,” NWS Boston tweeted Thursday morning. “A low such as this is the normal high for this time of year.”
Wednesday’s recordbreaking high was exacerbated by a dew point of 69 degrees, which pushed the heat index up to 104 degrees in Boston. High temperatures with high dew points make for a hot and sticky combination, Sipprell said.
“You put the two together and it makes it feel that much more oppressive,” Sipprell said.
How hot was it Wednesday? Hot enough to set some new records!— NWS Boston (@NWSBoston) August 30, 2018
Boston set a new record maximum temperature for the day of 98. Providence tied its record maximum temperature of 95.
All four of our climate sites set new record maximum low temperatures for the date, too. pic.twitter.com/O6XTyEc9c7
The NWS weather recording stations on Nantucket and Block Island were the only ones in Southern New England that did not report temperatures of at least 90 degrees Wednesday. High temperatures on the islands Wednesday were in the mid-80s, the NWS said.
It’s still too early to tell whether next summer will match the heat of the last few months, Sipprell said, but for now, Bostonians can look forward to gradually lower temperatures as fall approaches.