The meteorological summer came to a close at the end of August, but according to the sun's angle and the tilt of the earth, it ends Saturday at 10:48 a.m. (because fall starts at 10:49 a.m.).
Why is there difference? Meteorologists have always kept records based on temperature trends. The meteorological summer runs from June 1 through August 31, because that's when we experience the warmest temperatures.
Looking back, the summer of 2012 was a warm one! In July we had 17 days of temperatures of 90 degrees or hotter. We hit triple digits three days, one in June and two in July.
Only two high temperature records were broken this summer in Harrisonburg.
One was on June 29, the high was 104, beating the old record of 97 in 1927.
Does that date sound a little familiar?
That was also the date of the derecho (wind storm). The other record broken was July 7, breaking the 1977 record of 99 degrees.
Conditions were hot this summer, but not earth shattering. Keep in mind much of August was nice with temperatures at or below average. Through the summer, June highs were almost right on average, while July highs were almost 5 degrees above. Averaging each month this summer, our overnight lows stayed above the climate normals.
Let's be honest though, doesn't it already feel like we've started fall? The kids are back in school and those warm humid evenings are now cooler crisp nights. The sun is setting earlier and even the leaves have started changing! We've already been transitioning.
The earth rotates on a tilt and depending on the season, the northern hemisphere is tilted either towards or away from the sun.
The equinox (autumn/spring) is a time where the tilt of the earth and earth's orbit are more in an equilibrium, as shown in the graphic above. The sun's rays shine directly at the equator, neither the northern hemisphere or the southern hemisphere is pointed more towards the sun. Any equidistant latitude above or below the equator would get the same amount of energy from the sun, assuming clouds are not an issue.
By definition equinox means that the night and day are equal length. Although if you were taking this literally, the equinoxes aren't exactly 12 hours of daylight and 12 hours of darkness, but pretty close to it. Remember, the earth is still moving so this doesn't last all season! It's a quick change. We lose about 2 minutes of daylight each day shortly after the equinox in our area.
Don't forget about the Harvest moon!
It's the closest full moon after the autumn equinox.
This year it will be the night of Saturday September 29.
Let's hope for some nice, clear skies that night.