By Jeff Ray

(CBSDFW.COM) – As odd as it seems given the cooler weather of late, this is actually the last weekend of summer.

The Fall Equinox falls on Tuesday this year. This is when the noon-day sun sits over the equator. After this point the sun noon angle will center over a longitude south of the equator. Of course, all this is the result of the Earth tilting on its axis. As it rotates around the sun the northern hemisphere is either tilting TOWARD the sun (summer) or AWAY from sun (winter). The equinoxes are the halfway points between the two.

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The end result is that the days get shorter and colder as we head toward winter. When compared with the longest day of the year (the summer solstice back in late June) we’ve already lost about two hours of daylight here in the Metroplex.  By late December, just before Christmas, we’ve lost over four hours.

Of course the day-to-day weather doesn’t follow lock-step with the seasons or the calendars. We have enjoyed fall weather since we started September. Just last year we had the hottest September on record. This September has been the quite the opposite, just compare the monthly average temperature (as of the 17th) with last year and the average:

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Another way to compare this lack of September heat is to count the number of days where the daytime high gets to 90 degrees or above. Last year that happened 29 of 30 days of September! This year we have only logged 5 such days with none in the seven day forecast ahead.

The usual tandem of rain with the cooler temperatures is also part of the story. There was ZERO rain at DFW up to the 17th LAST YEAR.

Anyway, GREAT weather for the last weekend of summer. We are enjoying a two-day run of northeast wind from high pressure centered over the Great Lakes. They are getting their first freeze of the season in Michigan, but here we are just getting the dry air and slightly cooler temperatures. The dewpoints are forecast to drop all day long down into the low 50s. Highs will be in the low 80s under sunny skies. These temperatures are more typical of mid-October.

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Join me tonight on CBS 11 News at 6 p.m. and 10 p.m. for updates on Tropical Storm Beta, which is forecast to become a hurricane Sunday and close in on the Texas coastline by Monday.