Tuesday, February 26, 2013

Early & Late Seventies

We're approaching that time of the year when talk of the first warm day begins to percolate through the weather world.  As of now, those warm days are limited to tomorrow (mid and upper 50's) and that's about it for the next couple of weeks as March will start on a cool note overall.  That's in stark contrast to last March, which featured a tied of nine days of 70 degree weather or warmer, including eight in 11 days.  If you recall how quickly things greened up last year, you can thank the very warm start to the year for that.

It does not look like we will have such a similar trend this year.  A more traditional, not as warm, start to March is in the offing.  That doesn't mean we won't have the shot at the rogue warm day or two here and there -- most years feature a crack or two at 70, perhaps a run at 80, during the month of March.  It's reality in this part of the world.  Early Spring weather is incredibly, notoriously, fickle and is prone to rather wild swings in temperature over a short duration of time...but warmth is certainly a potential outcome as the month progresses.

It's been since 2008 since we haven't hit 70 in the month of March -- and before that, 2005 and then 2001.  Only three times since Y2K have we not "gone there" in the temperature realm.

Going back to 1950, the range of "first" 70 degree days is pretty wide.  We've had them as early as January 6th (1950 and 2007) to as late as April 26th in 1984. In fact, in 1982, 1983, and 1984 we went until the middle or latter April in each of those years before we had our first 70 degree day.  It's the only stretch in Philadelphia since the climate site was moved to the Airport in 1940 where our first 70 degree day didn't occur prior to April 1st in three straight years.

That said, if we go back to before 1940, other stretches of slow starts include 1915-1917, 1875-1879, and 1881-1887.  Yeah, in the 1870's and 1880's we weren't getting that first warm day before April 1st as often as we are now and we went seven straight years where the locals had to wait until April for the first foray into the 70's.  It's a different era now...and more often than not we usually see our first 70 before next month is out.