Philadelphia may go the entire month of August without a single 90-degree day.
Forecasters say high temperatures of 89 degrees are expected today and Wednesday, though there's a chance the mercury could hit 90 either day.
And those two days are likely to be Philadelphia's last chance for a 90-degree August day. The National Weather Service says the temperature is unlikely to reach that mark on Thursday, Friday or Saturday.
The hottest day of the month so far has been Aug. 21, when the mercury hit 89 degrees.
It is unusual for August temperatures to remain below 90 degrees. If the temperature doesn't reach 90 this week, the month will be Philadelphia's first August without a 90-degree day since 1984.
Over the past century, the temperature has failed to reach 90 in August just five times, according to the weather service. The years 1920, 1927, 1934, 1963 and 1984 all had Augusts without 90-degree days.
Philadelphia usually has six to seven days in August with temperatures of 90 degrees or above. Last year, there were eight 90-plus days in August, and there were four such days in August 2011.
This July, there were 12 days with temperatures in the 90s.
August has been cooler than normal in Philadelphia. The overall temperature for the month has averaged 74.1 degrees, 2.9 degrees below normal, according to the weather service.