September 2021 ranks as the second-wettest month of September on record with the National Weather Service.
A gauge at the Eastern Snyder County Regional Authority sewer treatment plant south of Selinsgrove measured 12.01 inches of rainfall last month, according to National Weather Service Meteorologist Aaron Tyburski.
The only greater measurement on record came in September 2011 when 18.93 inches of rain fell, Tyburski said, in large part due to the remnants of Tropical Storm Lee.
“I think it’s safe to say that around the area it’s the second-wettest September on record,” Tyburski said.
According to National Weather Service data, the following months of September are the five wettest as measured at the treatment plant: September 2011, 18.93 inches; September 2021, 12.01; September 1999, 11.48; September 1934, 10.2; September 1912, 9.18.
Average rainfall at this site is 4.41 inches, the data shows.
Tyburski reviewed data at the Penn Valley Airport that puts September 2011 at the top with 18.17 inches. Data from 1958 and 1997 is unavailable, he said. A combined 9.42 inches was measured last month.
However, Tyburski said the total is likely higher. Data collection from the airport for September 2021 was disrupted because of flooding at a Federal Aviation Administration communication center in upstate New York, he said.
“When we had the big rains from (Hurricane) Ida, it got flooded. It took them about 10 days to get in there and get the water out,” Tyburski said. “We likely missed a couple inches of rain.”
What was unusual about September 2021 is that the rain wasn’t largely brought on by tropical storms like in the past, Tyburski said. Several thunderstorms more typical in late July and August accounted for some of the totals.
Ida brought 5.43 inches on Sept. 1-2 as measured at the treatment plant, National Weather Service data shows.
“The remainder of the rainfall was slow moving thunderstorms, and a slow moving cold front at the end of the month,” Tyburski said.
Eric Nyerges, manager of the Union County Conservation District, and staffers Sadie Borger and Randy Ross previously said last month that heavy rains were challenging erosion controls at building construction sites, potentially dragging more sediment into streams. They said the heavy rains — there were four days of rain from 1.25 to 1.54 inches plus 4.9 inches in a single day from Ida — could interrupt harvesting.
Bill Zeiders, co-director of communications, Pennsylvania Farm Bureau, expressed less concern at the time about the potential for crop damage. Unless a field is completely flooded, most crops like corn and soybeans won’t be affected much, he said.
“If a farmer plants in an especially low field or near a creek that is prone to flooding, the farmer has already accounted for that. Weather is all part of the job, and is always on the farmer’s mind,” Zeiders said previously.