Pennsylvania Weather Review: September 2026
Pennsylvania Weather Review: September 2026
September certainly started off very busy, continuing the active trend from the summer months. As the month progressed the activity calmed down but it did remain wet as the transition to fall began. I will look back at the September weather highlights from Pennsylvania below.
September Highlights
 |
| Severe warnings and storm report summary from September 1, 2026. |
The first day of climatological fall was hot and humid in Pennsylvania. Temperatures on the first day of the month were warmer than any day during month of August in many locations. A stalled out front north of Pennsylvania sparked storms that would move southward through portions of northern and eastern Pennsylvania. The storms brought damaging wind and three tornadoes touched down.
 |
| Heat Index values from 4:30pm on September 2, 2026. Source. |
Heat Advisories were issued for portions of the state on the 2nd. Heat Advisories in September are not that common with Heat Advisories being issued in just 3 Septembers between 2006 and 2025. Locations in western Pennsylvania recorded a heat index of over 100°!
 |
| Severe warnings and storm report summary from September 2, 2026. |
With the stalled cold front sitting over Pennsylvania, more rounds of storms impacted the state. Storms over Lake Erie moved southward early in the morning, developing into a bow echo that dropped south through central Pennsylvania into the afternoon. By late afternoon another round of discrete cells began to develop in northern Pennsylvania. One intense storm came off Lake Ere around 10pm bringing widespread damaging straight line wind to parts of Erie. The damage caused nearly all of Presque Isle State Park to be closed through the Labor Day Weekend.
 |
| River gauge observations from Bald Eagle Creek at Beech Creek. Note the rapid rise observed around midnight of September 3, 2026. Source. |
Not all of the impacts were severe weather related. Intense flash flooding impacted portions of Centre and Clinton Counties where over 5 inches of rain fell in a few hours. Bald Eagle Creek near Beech Creek rose to 15.12' into Major Flood Stage. The water rose nearly 4 feet in 3 hours between 9:30pm and 12:30am on the 3rd. This is preliminarily the 4th highest crest on record.
 |
| Severe warnings and storm report summary from September 3, 2026. |
The storms didn't stop. A round of storms on the morning of the 3rd impacted western Pennsylvania with damaging wind. While not as impactful as the line pushed through southern portions of the state, it did provide incredible views of a long lived shelf cloud into south central Pennsylvania.
 |
| 72 hour observed precipitation ending 8am September 4, 2026. Source. |
One more round of storms late on the 3rd prompted the Storm Prediction Center to place portions of western Pennsylvania under a Marginal Risk (level 3 out of 5) for severe storms. Southern and western Pennsylvania were heavily impacted as storms formed a large bow echo. Widespread wind damage pushed the number of power outages over 160,000 in the state. Heavy rain falling on already saturated soil resulted in more flash flooding especially in the Pittsburgh Metro. One of the hardest hit areas was Johnstown where the recovery took days to cleanup from the straight line wind damage.
 |
| Power outage map as of 10:08pm on September 3, 2026. Source. |
As the Labor Day weekend arrived high pressure moved in giving a much needed break from the storminess. Most of Pennsylvania remained dry from the 4th through 8th. A cold front on the 9th brought a line of thunderstorms to northern and western Pennsylvania. While the storms were mostly non-severe there was some flash flooding and one tornado that touched down in McKean County.
 |
| 48 hour observed precipitation ending 8am September 14, 2026. Source. |
Another break brought calm conditions for the 10th and 11th before another cold front on the 12th. Heavy rain was once again observed in western Pennsylvania with localized totals of over 3 inches. It started feeling more like fall as temperatures and dewpoints would begin to drop. Morning lows on the 15th were in the 40s for most of the state.
 |
| 2m dewpoints at 1:30pm on September 17, 2026. Source. |
The coolness didn't last as dewpoints would rise into the 70s by the 17th. Some pop up showers impacted northwestern and south central Pennsylvania on the 16th. with more scattered showers and storms on the 17th. Thankfully these storms were non-severe. The calm weather returned for the 18th an 19th with low humidity and dry conditions.
 |
| 24 hour observed maximum temperatures ending 8am September 23, 2026. Source. |
A damp and dreary period would arrive on the 20th with a period of rain in the early morning hours of the 20th. Scattered showers continued into the daytime hours but for most locations overcast with light rain and drizzle remained all day. It was humid on the 20th but that would go away in the 21st. The rain however stayed making for a cool damp day. Nearly 2 inches fell in some locations of central Pennsylvania. The dreariness continued into the 22nd and was even cooler. Temperatures for portions of the Laurel Highlands and Alleghenies did not rise out of the mid 50s!
 |
| 24 hour observed minimum temperatures ending 8am September 25, 2026. Source. |
Conditions would remain cool, but the rain ended an the clouds cleared for the 23rd and 24th. Combined with low dewpoints, these conditions were the perfect recipe for the first Frost Advisories of the season on the morning of the 25th. Temperatures dropped into the 30s for much of the state.
 |
| 72 hour observed precipitation ending 4:00pm September 28, 2026. Source. |
While the major impacts of a nor'easter were along the east coast, some wind and rain did impact eastern Pennsylvania. The highest rain totals were confined to southeastern counties with over 2.50" to 3.50" falling in the Philadelphia Metro. Some showers did propagate westward into central regions on the 27th. The 28th and 29th featured dry conditions with overcast for much of the state. The 30th was also quiet with a foggy start followed by a mix of sun and clouds.
 |
| A spectacular sunset courtesy of the nor'easter was observed at Cherry Springs State Park in West Branch on September 26, 2026. Source. |
September Statistics
 |
| Temperature and precipitation summary for September 2026. |
Temperatures for the month of September 2026 were near to well above average. Pittsburgh was 3.7° warmer than average and Philadelphia was 2.5° warmer than average. It was wet for most of the state, too, with most locations 1.00"+ above average. Allentown, Harrisburg, and Scranton all had near average precipitation.
 |
| Precipitation totals, departures, and ranking for August-September 2026. |
Since August 1st a large portion of the state has recorded over 10 inches of precipitation with departures of more than 5 inches. It was also a top 10 wettest August-September for much of the state- impressive given that there was no tropical influence! Some localized spots measured over 20 inches over the two month period!
 |
| Map of total precipitation for August-September 2026. Source. |
159 Severe Thunderstorm Warnings were issued in September 2026. The previous most was 93 in 2023. All but 13 of these were issued on the first 3 days of the month! 25 Tornado Warnings were also issued in the state this month. The previous September record was 13 in 2021. This pushes the total number of Tornado Warnings for 2026 to 100 second only 1998 (109).
 |
| Severe warnings and storm report summary from September 1-3, 2026. |
A total of 314 Convective Storm Reports (Tornado, Thunderstorm Wind Gust/Damage, and Hail) were collected by the National Weather Service. The previous most for the month of September is 150 in 2012.
September Tornadoes
There were an additional 4 tornadoes in Pennsylvania this September. Three occurred on the first day of the month, all rated EF1. An additional EF1 tornado touched down in McKean County on September 9th. This was the first tornado in McKean County since 2003!
 |
| A list of the 4 tornadoes observed in September 2026. Source. |
4 tornadoes in September is tied for the 4th most number of tornadoes to be observed in September. The record is 9 set in September 2004. This brings the total for 2026 to 50!
Eye on Drought
 |
| Pennsylvania Drought Monitor as of September 29th. Source. |
Drought conditions in southeastern Pennsylvania improved greatly in September thanks to the beneficial rain. 0.91% of the state remains in Moderate Drought with 3.68% in Abnormally Dry conditions. The most recent report from September 29th does place parts of Erie County in the Abnormally Dry category.
 |
| Drought classification change map comparing September 1st to September 29th. Source. |
Webcam Image of the Month
A stunning shelf cloud traversed much of the state on the morning of September 3rd. This view from Willow Hill shows that the base of the cloud was below the distant ridgetop!
 |
| A shelf cloud approaches Willow Hill on September 3, 2026. Source. |
Wrapping Up & Looking Ahead
The leaves are changing and the air is crisper. Hopefully you can get plenty of time to enjoy the fall weather and fall foliage.
As always, remember to look up! 🌤️
Comments
Post a Comment