Alaska's Mount Redoubt keeps spewing ash.  A 12 mile high cloud could be seen Thursday, March 26th, rising from the volcano.

The volcano has been active for most of the week, but there was a lull in the eruptions for most of Wednesday, March 25th.  When Redoubt last erupted 20 years ago, it went on for four months.

Okay, let's look at the numbers.  Redoubt last blew its top from December 1989 to April 1990.

What kind of summer did we have in Philly in 1990, you ask ?
Great question.  After a freak heat wave in the spring, April 26th to 28th (3 days at 90)...

We had 20 90 degree days in the summer months.

June  2 days  (first 90 degree day on the 29th)
July  9 days  (1 heat wave - 3 consecutive days or more)
August  6 days (1 heat wave - 3 consecutive days or more)
September 3 days

2 days in the 60s, August 20th and 21st, 1990.

Keep in mind, 1990 was the start of a very warm El Nino period.
We are NOT in that pattern now, as we are still in a weakening period of La Nina.

Plus, there are fewer sunspots today --- more evidence of a cooling trend.

Normal (or 30 year average) for Philly is 20.5 days at 90 degrees or higher. 

Here is a look back...

2006
27 days at 90 degrees or higher

2007
24 days at 90 degrees or higher

2008
23 days at 90 degrees or higher

2009
FEWER days at 90 degrees or higher

I am convinced that the chances of hitting 100 degrees this summer are less, if not, slim.

And I am also convinced at this time that we will have an AVERAGE summer, in regards to 90 degree days, if not, FEWER than normal. 

My prediction is for 17 to 22 days at 90 degrees or higher at Philly International Airport.