BETHLEHEM, Pa. — It is all but certain, forecasters say, that the Lehigh Valley will not see a 90-degree day in the month of August.
Not with cooler-than-average air headed for the region this week.
- The Lehigh Valley did not have a 90-degree day — measuring air temperature — during August
- It likely will mean our coolest August in almost a decade
- With El Niño in full swing, could it be a sign for what's to come this winter?
So, that benchmark that truly says "summer" — when is the last time we failed to hit 90 during what is normally one of the warmest months of the year?
"Those back-to-back years of the last time we failed to reach 90 in August were in 2013 and 2014," EPAWA meteorologist Bobby Martrich confirmed Monday.
As a cold front arrives this weekend, forecasters say a pool of air from a Canadian high — a large, weak semi-permanent atmospheric high-pressure center produced by the low temperatures over northern Canada — will build south toward our region.
In summer, the Canadian high usually is intermittent and occasionally dumps cool, dry air into the central and eastern United States.
Since it’s still summer, not winter, those “cooler” temperatures are forecast to bring us highs in the 70s almost straight through the end of the month, with overnight lows in the 50s.
If places such as the Poconos get the chilliest air, hoodies and jeans might even be required as overnight temps drop to the lower 50s (with the possibility of a night or two in the 40s).
It might just be a short-lived early fall, but make no mistake — it will likely put the cap on our coolest August in almost a decade.
Remember when?
In 2013, the Lehigh Valley's average mean temperature in August was 70.6 degrees. The following year it was 70.8 degrees.
This month should finish somewhere in that area after a first half that featured below-normal temperatures not only here in the Lehigh Valley, but across the Northeast.
“June ended up below average, July was near average, and this one is going to be below average without a doubt,” Martrich said.
Allentown’s average temp from Aug. 1-15 was 72 degrees, or 2.6 degrees below average. Of the 35 major climate sites monitored by the Northeast Regional Climate Center, it also was the third-coldest; 29 of the 35 climate sites also were cooler than normal in that period.
Looking back, 30 of the climate sites were cooler than normal during August 2013. The following year, 33 of the climate sites were cooler than normal during August.
What does it mean, if anything?
If you ask a meteorologist, it’s probably clear as mud what this means or what, if anything, it portends.
“I don’t know if the implied connection [to a potentially snowy winter] has merit,” Martrich said.
"I don't know if the implied connection has merit."EPAWA meteorologist Bobby Martrich, on our cooler August possibly being a clue to the upcoming winter
With El Niño in full swing, the global configuration of weather systems plays a big role, and odds of a strong El Niño continuing now are more than 95%.
The strongest climate impacts usually are felt during the Northern Hemisphere’s winter and early spring, and this El Niño could last through February 2024, the National Oceanic and Atmospheric Administration said last week.
Eight of the Lehigh Valley’s 10 snowiest seasons on record have had an El Niño component.
That includes the winter of 2013-14, when 68.1 inches of snow blanketed the area — our third-highest seasonal snowfall total since records began in 1944.
The following year, the region's first accumulating snow of winter came in November. Months later, all of the major climate sites finished with snowfall totals at or above normal (including Allentown, which finished at 50.1 inches).
Many areas also saw their coldest February ever and one of the coldest months of all time.
