Philly weather is a mood. Honestly, if you’ve lived here long enough, you know the drill: one day you’re wearing a parka at a SEPTA stop, and forty-eight hours later, you’re sweating through a t-shirt in Rittenhouse Square. It's erratic. It’s gritty. And looking back at the data for past weather Philadelphia PA, it’s clear that our "normal" is anything but.
Most people think of Philadelphia as just another humid East Coast city. That's a bit of a simplification. We sit in this weird transition zone—the humid subtropical climate meets the humid continental zone—and that tug-of-war is exactly why our weather history is littered with record-breaking heatwaves and blizzards that literally shut down the city for a week.
The Big Heat: Records That Still Sizzle
When you talk about the absolute peaks of past weather Philadelphia PA, you have to start with August 7, 1918. That was the day the mercury hit 106°F. It remains the all-time record high for the city. Imagine 1918 Philly—no modern air conditioning, just brick rowhomes soaking up the sun like ovens.
But it’s not just the old-school records that matter. We're seeing a massive shift lately. Looking at NOAA (National Oceanic and Atmospheric Administration) data, the 21st century has been significantly warmer on average than the 20th. July is typically the hottest month, with an average high around 87°F, but we’ve seen plenty of recent years where 90-degree days become the rule rather than the exception. In 2024, for example, the Mid-Atlantic region experienced a "top-10" warmest year on record, a trend that continued right into the start of 2026.
Humidity is the real killer here. Because we’re tucked between the Appalachian Mountains and the Atlantic Ocean, that moisture gets trapped. It basically turns the city into a swamp by mid-July.
Snowmageddon and the Great White Outs
If you want to start an argument in a Delco bar, just ask which blizzard was worse: '96 or the 2010 back-to-back hits.
✨ Don't miss: Deep Wave Short Hair Styles: Why Your Texture Might Be Failing You
The Blizzard of 1996 is the heavyweight champion. Between January 7 and 8, the city was buried under 30.7 inches of snow. That’s the single greatest three-day snowfall in Philadelphia’s recorded history. It paralyzed the entire region. People were literally skiing down Broad Street because cars weren't going anywhere.
Then there was the winter of 2009-2010. That was the season of "Snowmageddon." We didn't just get one big hit; we got a relentless sequence.
- December 2009: A massive 23.2-inch dump.
- February 2010: Two separate storms that brought 28.5 inches and 15.8 inches respectively.
By the time the dust (or flakes) settled, the 2009-2010 season had racked up 78.7 inches of snow. For context, the average annual snowfall for Philly is usually only around 23 inches. We tripled it in one year.
Philadelphia's All-Time Snow Records (The Short List)
- January 7–8, 1996: 30.7 inches (The King)
- February 11–12, 2006: 26.9 inches
- January 22–23, 2016: 22.4 inches (Winter Storm Jonas)
- February 5–6, 2010: 28.5 inches (Part of Snowmageddon)
When the Rain Doesn't Stop: Flooding and Hurricanes
Philly isn't technically a coastal city, but the Schuylkill and Delaware rivers don't care about technicalities. Tropical remnants have a history of wrecking the place.
Hurricane Sandy in 2012 is the one everyone remembers for the wind and the surges, but Hurricane Floyd in 1999 was a different beast entirely. Floyd dropped a staggering amount of rain—over 6 inches in some parts of the city—causing the Schuylkill to crest at levels that flooded the Vine Street Expressway.
🔗 Read more: December 12 Birthdays: What the Sagittarius-Capricorn Cusp Really Means for Success
More recently, the remnants of Hurricane Ida in 2021 reminded everyone how vulnerable the city's infrastructure is. The Schuylkill River reached 16.35 feet, its highest level in over a century. Seeing the "Big Dig" (I-676) turned into a literal canal was a wake-up call that the past weather Philadelphia PA isn't just a collection of dusty stats—it’s a preview of what happens when the planet warms up.
The Weird Stuff: From Derechos to Earthquakes
Weather isn't just rain and sun. Sometimes it’s a "Derecho." On June 29, 2012, a line of fast-moving, high-intensity thunderstorms tore through the city with winds topping 70 mph. It felt more like a hurricane than a summer storm, knocking out power to hundreds of thousands of residents for days during a heatwave.
And while it’s not strictly "weather," the 2011 Virginia earthquake (5.8 magnitude) felt like a weather event to most Philadelphians. The ground shook, buildings in Center City were evacuated, and for about ten minutes, every cell tower in the city was jammed.
Making Sense of the Shift
So, what does all this data actually tell us? Basically, Philly is getting warmer and wetter.
According to the Philadelphia Mayor’s Office of Sustainability, the number of days over 95°F has been creeping up steadily over the last few decades. We’re seeing fewer of those "classic" winters where it stays cold from December to March. Instead, we get these wild swings: a 60-degree day in January followed by a flash freeze.
💡 You might also like: Dave's Hot Chicken Waco: Why Everyone is Obsessing Over This Specific Spot
If you’re looking at past weather Philadelphia PA to plan a move or just to settle a bet, keep these nuances in mind:
- Winter is a gamble: You might get 2 inches total, or you might get 70.
- Summer is a swamp: Plan for high dew points from late June through August.
- The "shoulder" seasons (May and October) are elite: These are the months when Philly weather actually behaves.
How to Use This Information
If you're a homeowner or a traveler, don't just look at "average" temperatures. Those averages are made up of extremes. Check the historical "daily mean" for your specific dates, but always look at the record highs and lows to see what the atmosphere is actually capable of.
For the most reliable deep-dives, stick to the National Weather Service (NWS) Mt. Holly office—they handle the Philly region and have archives going back to the late 1800s. The Franklin Institute also maintains a fantastic local database if you want to see how the weather looked from a "Center City" perspective specifically.
If you are prepping for the upcoming season, your best bet is to look at the three-year rolling average rather than the 30-year "norm." The 30-year norm includes a climate that arguably doesn't exist in the Mid-Atlantic anymore. The last decade provides a much clearer picture of the volatility you should expect. Check your sump pumps in August and keep your salt spreaders ready by early December. Philly weather doesn't give many warnings before it decides to break a record.