September 1st marked the start of Meteorological Fall. Yes, the astronomical summer season continues until the Fall Equinox that this year falls on September 22nd near midnight. Yet, the meteorological fall months of September, October, and November better represent what the time of year feels like.
For instance, the months of December, January, and February mark Meteorological Winter – the coldest months, while June, July and August are the hottest months of the year and are Meteorological Summer.
Astronomical Fall, commonly called the first day of fall, starts with the Fall Equinox and runs through until the Winter Solstice, or the shortest day of the year in late December. So the difference between the Astronomical and Meteorological seasons simply comes down to the start and end dates.
If it seems that summer is running longer in recent years, your sense would be correct. Studies have shown that since the 1950’s, the summer season is now on average 3 weeks longer, starting earlier in the spring and extending into fall. Recall last year that high temperatures soared into the 80’s on Sunday October 16th, the warmest ever for so late in the year – serving as yet another example.
Regardless, fall is just around the corner as the days get shorter and the nights longer, and cooler wetter weather returns. In the meantime, enjoy what summer weather remains!