The temperature in Buffalo doesn't hit 90 degrees often in September, but when it does, it often happens more than once.
On Sunday, the temperature at Buffalo hit 90 degrees. It made it to 91 degrees on Monday.
This is the warmest air of 2017 — three days into autumn. The year's previous high temperature, 89 degrees, came June 17.
Sunday's record-breaking heat was the first 90-degree reading during September in Buffalo since Sept. 3, 2012, and the 26th time a 90-degree day was recorded here since official weather record-keeping began in 1870. Monday's was the 27th. Out of those 27 days, consecutive 90-degree days account for 13 of them.
Weather service data shows there was a four-day string of 90-degree days from Sept. 1-4, 1953, with temperatures ranging from 90 to 98 degrees.
The 98-degree mark from Sept. 3, 1953, stands as Buffalo's highest temperature on record in September.
Other years with consecutive 90-degree days included three-in-a-row from Sept. 12-14, 1952, and back-to-back days on Sept. 6-7, 1945, and more recently, Sept. 6-7, 2007.
Monday's temperature record — 87 degrees in 2007 — fell this afternoon. The temperature peaked at 91 degrees about 2:52 p.m.
Tuesday's record — 87 degrees in 1959 — looks to be in jeopardy, too.
It's more than 20 degrees above average. The average daily high temperature in Buffalo for Monday is 67 degrees.
Monday was also the 10th day in a row the temperature reached at least 80 degrees.
That's September's second-longest streak on record in Buffalo. It reached 80 degrees for 13 straight days from Sept. 3-15, 1947.
Weather service forecasters said the unusual heatwave is being caused by a sustained ridge of high pressure, combined with equatorial air being brought northward by hurricanes Irma and Jose.