Despite April’s flirtation with temperature normality, the first four months of the year constituted the warmest such period on record in Philadelphia.
The average temperature from Jan. 1 through April 30 at Philadelphia International Airport, 46.6, nipped the old standard of 46.3, set in 1921.
And, yes, it continues to be dry. The mere 7.7 inches of precipitation in a period that included one of the most snow-less winters on record resulted in Philadelphia’s fifth-driest first four months of the year.
Official recordkeeping dates to 1874.
With a chilly finish that featured nine consecutive days of below-normal temperatures – the longest such streak in over a year – the April average of 55.5 was only about 1.5 degrees above normal.
Still, the Jan. 1-April 30 temperature was almost 6 degrees above.
“It’s an amazing run,” said Anthony Gigi, a meteorologist at the National Weather Service office in Mount Holly.
It's especially amazing considering that with general warming, "normals" are higher than they used to be. The current ones were calculated using the 1981-2010 period.
The April "normal" is about a degree higher than the one computed using the 1971-2000 period.
As for global warming’s possible role this year, Philadelphia and much of the United States have been at odds with trends in the rest of the world, according to the National Climate Data Center.
January, February, and March were cooler globally, compared with those same months in recent years, and last month was the coolest March since 1999’s.
Meanwhile, for the fourth consecutive month, nature continued to be stingy with precipitation, and rain deficits now are common throughout the Midatlantic states.
Precipitation is 60 percent of average or lower in Philadelphia and all the neighboring Pennsylvania and New Jersey counties.
The heavy rains of 10 days ago notwithstanding, last week the U.S. Drought Monitor placed all of New Jersey and most of eastern Pennsylvania in a state of “moderate” drought.
The drought map is scheduled for an update tomorrow.