09/23/11 First Day of Fall

Today was the first official day of Fall at 5:04am ET/2:04am PT. While the meteorological start to Fall happened on September 1st, the astronomical Fall begins today when there are near equal amounts of sunlight no matter where you are located on the Earth. Twice a year, once in the Spring (around March 20 or 21), and then again in the Fall (around September 22 or 23), the sun's rays shine directly over the Earth's equator. The first days of Spring and Fall correlate to these days, often called vernal equinox (Spring) and the autumnal equinox (Fall). While it is great that everyone receives the same amount of sunlight today, it also means that the days will grow shorter each day as we approach the first day of Winter (in the northern hemisphere).

However, just because the calendar says it's Fall, doesn't mean Mother Nature got that message. If you told folks in Phoenix it was the first day of fall, they might ask where? Today's high in Phoenix is set to be 108°, and going into the weekend, it will likely only drop about 2-3 degrees. Parts of Mid to Southern California were expected to have highs in the low 70s with off and on showers with even a few thunderstorms with blustery winds. Not exactly ideal fall weather. Areas of the southeast are expected to be covered in thick clouds with scattered showers and a few thunderstorms. Highs will be mainly in the upper 60s  to low 70s for the Mid-South. In the northern plains states things feel more like summer with temperatures at least 10 degrees above normal. In fact, in Missoula, Montana the high temperature today is expected to be 15 degrees above normal, and tomorrow it will be 20 degrees above normal, potentially breaking a record high! And in Texas, where summer just doesn't want to go away, some relief is finally in store for them. Houston will be in the low 90s today, and likely stay there for the weekend. For folks in Dallas, thanks to some fog, haze, and a little more cloud cover, temperatures will only be in the mid 80s. And in Austin, where there were 85 days of triple-digit heat this summer (shattering the previous record of 69 days set back in the 1920s), today's forecasted high of low 90s doesn't sound too bad. Although, it will shoot back up to the upper 90s for the weekend.

So what are temperatures typically like for the first day of Fall? Below is a look at the averages across the country for both highs and also low temperatures.