As you're likely aware, it's been a warm year as temperatures are off to their warmest start on record in Philadelphia as temperatures are four degrees above what's considered normal for us and nearly a degree above the old record pace from 1991. Not every day has been warmer than average but a good chunk of them have.
I went back and did a simple breakdown of above/below/normal days since January 1st. In such a breakdown like this, "normal" is going to take the lowest percentage of days since it's focusing on a singular data point and not a spectrum of numbers (above or below average). In terms of a pure above/below standpoint, we've been above average 139 times this year for daily temperatures while below average just 50. June was the only month this year to feature half or more of its days with below average temperatures -- 15 of the 30 days were below average for the month, with the month the coolest for the year compared to normal as temperatures ended up just a couple of tenths above average.
Focusing on temperature spreads within each range -- the number of days so far this year where the average temperature for a day was ten or more degrees above average is 38. We've seen only three days where the average temperature was ten or more degrees below average this year -- once in January, twice in April -- and in all three instances the coldest from average we ended up was eleven degrees. We've had seven days where the average temperature was more than twenty degrees above average this year -- mostly in February and March.
Whether you want to blame global warming, climate change, oceanic influences, urbanization (heat island)...any combination of the four...there is a pronounced shift towards warmth this year in our neck of the woods and across much of the US. Our intent is not to pin the blame on any one factor or combination of factors but to state what's going on out there and highlight the facts that back just how warm this year has been. And when seven in ten days are above average on temperatures, years like 2012 are going to result.