Since the beginning of the year, Pennsylvania has gotten so much rain — 40.2 inches just through August — it has smashed every eight-month rainfall total since 1895, when record-keeping began.

An Inquirer analysis of National Weather Service data also shows that the January-through-August average since 1895 has been 29.1 inches. And this year's record doesn't even include last weekend's drenching. The impact of Hurricane Florence, though it's too soon to predict, could mean far more precipitation is on the way.

In general, the areas north and west of Philadelphia have been hit the hardest, with Reading seeing more than triple its historic average level of precipitation the last 30 days.

NOAA map of rainfall totals Jan. through Aug. 2018.
National Oceanic and Atmospheric Administration
NOAA map of rainfall totals Jan. through Aug. 2018.

Forecasters and officials are watching Florence's track closely to see what it could mean for an already soggy state.

"We don't know the path Florence will take and if it will even affect us," said Jeff Kolakowski, a representative for Philadelphia's Office of Emergency Management.

Heavy precipitation has caused havoc almost from the start of the year.  Late February into March saw several  nor'easters, one of which turned deadly as an optician from Upper Merion was killed when a tree crashed down.

Summer has been abnormally wet, leading to fears of mosquito-borne illness such as West Nile virus.  Pennsylvania officials say it was a record year for mosquitoes because of the rain.  Rainfall from June through August in Pennsylvania was way above average in many areas of the state.

Pennsylvania's average total summer precipitation, dating back to 1895, is 12.4 inches.  This summer it was 18.8 inches, or 51 percent above normal.

Philadelphia recorded 7.20 inches from Friday through Monday afternoon. That brings the total to 40.37 inches for the year — or 11.30 inches above average.

Philadelphia’s Wet Year

Through Sept. 9, Philadelphia has officially recorded over 40 inches of precipitation, 11 inches more than normal, and almost as much as the city’s annual average.
Staff Graphic

In addition to the death in Upper Merion, this year's rains have had an extraordinary impact. Some examples from the summer:

  • In June, a 30-year-old photographer was swept away in a flash flood in Philadelphia's Pennypack Park.
  • In Central Pennsylvania, up to 11 inches of rain fell over five straight days in July.  Hersheypark was forced to close for days. A woman was killed in Elizabethtown, Lancaster County, when she was swept away into a creek.  That same week, record rains carried tons of sediment and debris from Pennsylvania into Maryland when water rushed over the Conowingo Dam.  The rains were so intense that Exelon, the power company that operates the dam, had to open 20 floodgates and the debris made its way into the Chesapeake Bay.
  • In August, Gov. Wolf declared a state of emergency when downpours and floods ripped through parts of the state, including Delaware, Bradford, and Schuylkill Counties.
  • Flooding has become more routine in coastal South Jersey, which was hit hard by the nor'easters and heavy downpours throughout the summer.  As of Monday, areas such Egg Harbor and Ocean City were dealing with flooded streets from the heavy rains that started falling Friday. Florence and its remnants could aggravate an already difficult situation.

Alex Staarmann, a meteorologist with the National Weather Service office in Mount Holly, said it's too soon to know what Florence will mean for the Philadelphia and South Jersey region.

"The further north it tracks, the more an impact it would have on Philadelphia and South Jersey," Staarmann said. "However, regardless of where it ends up, we'll still have concerns for coastal and marine zones with high rip currents and surf, and more coastal flooding."

Staarmann noted that whatever additional rain comes, it will be hitting ground that already is saturated. That means strong winds could topple trees.

"That certainly leads to more concerns with flooding potentially for this weekend," Staarmann said. "It's been quite wet this year."

Current National Hurricane Center projections have Florence making landfall in the Carolinas on Friday. Dave Dombek, a senior meteorologist with AccuWeather, said forecasters should have a good idea by Wednesday of Florence's potential.

"One scenario is that Florence slows down and stalls, and rains itself out over the Carolinas. That would not have much impact (in Philadelphia)," Dombek said. "Another scenario is that it continues on a northwest course that takes it over the Smoky Mountains and toward the Ohio Valley, bypassing the Philadelphia area.

"And of course, one scenario is that it does slow down and comes northward carrying tons and tons of tropical moisture," he continued. "So you'd be looking at it having an impact this weekend. You could be looking at anywhere from an inch or 2 to 5 or 10 inches.  That's a worst-case scenario.  But, at this juncture, I don't have any answers yet."

David Robinson, a Rutgers University professor and New Jersey state climatologist, said that although summer rainfall was close to normal in his state, it's been a wet year overall for South Jersey, especially so far in September. Already, just 10 days into the month, many areas have seen more rain than in an entire normal month.

Robinson said the big concern in New Jersey is the coast, which has already experienced moderate flooding since the weekend.  Coastal flooding comes from ocean water being pushed toward the shoreline by winds.

"So it's going to be very unsettled for the next week," Robinson said. "And we might be counting our lucky stars if that's all we have to say about it."