An extraordinarily wet start to the month of April has pushed what was already a very damp 2024 in Pittsburgh into all-time record territory, as the region is off to its wettest start of a year since the data began being recorded in 1870, according to a WESA analysis of National Weather Service data.
As of Thursday, Pittsburgh has received 17.58 inches of precipitation. The next highest amounts of precipitation at this point in the year was in 2018 and 1890 — both years Pittsburgh received about 16.25 inches by April 11.
And if rainfall amounts up to this point are any indication, 2024 could be one for the books — 2018 and 1890 ended up being the wettest two years on record in Pittsburgh; this year is currently outpacing them both.
The record rainfall isn’t guaranteed to continue, according to John Darnley, the observation program leader at the National Weather Service’s Pittsburgh-area office. “It can change on a dime,” he said. “All we need is for high pressure to park over us” and that would push the moisture away from us.
Darnley looked at maps of rainfall in Southwestern Pennsylvania in the past 30 days and acknowledged that the levels are anomalous, with some areas north of Pittsburgh having received more than 15 inches. “That’s a little crazy,” he said.
This month is on pace to be the wettest April ever in the city, according to the National Weather Service. And — at 7.29 inches of precipitation so far — this month is already the third-wettest April in history; the current rainiest fourth month of the year was 1901, when the city saw 8.11 inches.
Most of that rain has fallen over two very wet days. It rained 2.77 inches in Pittsburgh on Thursday, setting a new record for the wettest day ever in Pittsburgh, besting the previous record set earlier this month on April 2.
Darnley said the last time there were two major rain events this close together was in 2004 during Hurricane Ivan. “The pictures I saw from Oakdale yesterday and this morning look very similar to the pictures that I saw back in 2004,” he said.
Flash flooding caused by relentless heavy rains spurred numerous rescues and evacuations in the region, but no injuries were reported.
An extremely wet March had already shattered the record for most rain at the start of a Spring season in Pittsburgh.
Darnley said the reason for the large amount of rain on Thursday was that the area received moisture from two sources at once — the Great Lakes and the Gulf Coast. Normally, it would only receive moisture from one of these sources during a single precipitation event.
