When you’re planning for St. Patrick’s Day in Pennsylvania, you’ve really got to be ready for anything. Some years, you’ll get sunshine and that first taste of spring air, but other times, snow showers or a cold wind can show up out of nowhere.
Most years, temperatures land somewhere between the upper 30s and low 50s, and depending on where you are, you could see rain or even a bit of snow.
The weather varies a lot across the state. Philadelphia usually gets the milder, more springlike stuff, but up in Scranton or over in Erie, you might still feel stuck in winter.
This huge range makes it tough to predict, so it helps to know what usually happens around mid-March.
If you’re thinking about joining a parade, hanging out outside, or just traveling across Pennsylvania, it’s smart to check out the typical weather. Looking at temperatures, precipitation, and what happens in different regions gives you a better shot at avoiding surprises.
Typical St. Patrick’s Day Weather in Pennsylvania
Most of Pennsylvania sees cool temperatures, a decent chance of rain or snow, and breezy conditions on St. Patrick’s Day. March weather changes fast, so you really need to prepare for both winter chill and those early hints of spring.
Average Temperatures on March 17
On St. Patrick’s Day, the air usually feels chilly, but not bone-chilling. Average highs run from the mid-40s°F up north (think Scranton and Erie) to the low-50s°F down in the southeast (like Philadelphia).
At night, lows often drop near 30°F–35°F, and some valleys can even dip into the upper 20s.
Philadelphia sits at the warmer end, with highs near 53°F and lows around 36°F. Pittsburgh usually sees highs close to 51°F and lows near 34°F. Erie and Scranton tend to stay colder, with highs in the low to mid-40s°F and lows right around 30°F.
So if you’re heading to an outdoor parade or festival, you’ll probably want a jacket or coat. Afternoon sun might make things feel better, but mornings and evenings can be brisk.
Precipitation Patterns
March brings plenty of wet weather to Pennsylvania, and St. Patrick’s Day is no exception. Most cities see 8–9 days of measurable precipitation in March, so there’s about a 25–30% chance of rain or snow on any given day, including the 17th.
Philadelphia and Pittsburgh usually get more rain—March averages 2–3 inches of rainfall in those cities. Scranton and Erie often see a mix, with Scranton averaging over 4 inches of snow in March, and Erie picking up about 3 inches.
If you’re traveling for parades, it’s wise to bring an umbrella or waterproof jacket. Short showers and drizzle pop up a lot. In the north, you might even see snow flurries, especially in the morning.
Wind Conditions
Winds in mid-March can really add to the chill. On St. Patrick’s Day, average wind speeds run 8 to 12 mph across Pennsylvania, but open areas and spots near the Great Lakes can get stronger gusts.
Philadelphia’s winds usually feel a bit lighter, but afternoons can still reach 10–15 mph. Pittsburgh and Scranton get similar speeds, while Erie often faces stronger gusts because of Lake Erie.
These winds make it feel colder than the thermometer says, especially early in the day. If you’re watching a parade or spending time outside, layering up and grabbing a wind-resistant jacket will make things a lot more comfortable.
Temperature Ranges and Extremes
St. Patrick’s Day in Pennsylvania can swing wildly between late-winter chill and early-spring warmth. Some years, you wake up to snow; other times, afternoons feel more like May.
Historical Highs and Lows
Pennsylvania weather on March 17 has seen some wild swings. Most years, highs stick in the 40s or low 50s, but sometimes, temperatures shoot up into the 70s or even 80s during freak warm spells.
Cold snaps have brought morning lows down into the teens or even single digits, especially in the north and higher elevations. When late-season Arctic air shows up, it can get downright frigid.
Cities like Scranton and Erie have recorded highs barely above freezing some years, while Philadelphia has soared into the upper 70s on the same date. Where you are really shapes what you’ll get.
First 70-Degree Days
For a lot of Pennsylvania, St. Patrick’s Day lines up with the first real taste of spring warmth. In Philadelphia and the southeast, hitting 70°F by mid-March isn’t rare. Sometimes, March 17 even brings the year’s first 80-degree day.
Western and northern parts of the state usually have to wait until late March or April for that kind of warmth. Still, every now and then, a warm surge will push Pittsburgh or Williamsport much higher than normal.
Those early warm days feel amazing after weeks of cold. They draw bigger crowds to parades and festivals, but don’t get too comfortable—cooler air can always make a comeback. It’s smart to plan for both warm and cold.
Regional Temperature Variations
Pennsylvania’s geography creates big swings in St. Patrick’s Day weather. The southeast—Philadelphia and nearby counties—usually gets the warmest weather. Highs here often reach the upper 50s, and sometimes spike into the 70s.
Pittsburgh and the west run a few degrees cooler, with highs usually in the mid-40s to low 50s, but warm spells can still show up.
Up north, places like Erie and Scranton stay colder. Highs often stick to the 30s or 40s, and snow cover is more common. Higher terrain in the central mountains can keep things several degrees cooler than the valleys.
So, your St. Patrick’s Day experience can really depend on where you are in Pennsylvania.
Rain and Snowfall Trends
St. Patrick’s Day weather in Pennsylvania bounces between wet and wintry. Light to moderate rain happens in many years, but snow still pops up, especially in the north and higher elevations.
Likelihood of Rain
Rain shows up pretty often around March 17. You might see 0.10 to 0.25 inches of precipitation on that day, though some years bring more. The chance of measurable rain usually sits around 30–40%, depending on where you are.
Southeastern counties like Philadelphia get more rain than snow because it’s milder. Central and western Pennsylvania lean toward rain too, but cold air can still mix in, bringing brief sleet or wet snow.
March storms sometimes last for hours, but fast-moving cold fronts can bring quick bursts of rain and then clear out. If you’re planning something outside, expect damp ground and maybe bring an umbrella, just in case.
Snowfall Possibilities
Snow isn’t off the table on St. Patrick’s Day, especially up north and in higher spots like the Poconos or Laurel Highlands. These areas usually average less than 1 inch of snow on the 17th, but sometimes late-season storms dump several inches.
Central and southern Pennsylvania see less snow, but it’s not unheard of. You might get flurries or a light coating if colder air hangs around. Record lows in the teens have made snow possible in the past, but in warmer years, it just rains.
March is a big transition month, so snow can be all or nothing. Some years, there’s not a flake, while others bring enough to mess up travel. If you’re driving around the state, expect more snow risk in the mountains.
Notable Weather Events
Pennsylvania’s weather history for March 17 is all over the map. Temperatures have landed anywhere from the mid-teens to the upper 70s, which means you could get a snowstorm or a warm, rainy afternoon.
Northeastern Pennsylvania has had St. Patrick’s Days with snow-covered streets one year, and sunny 60s the next. Sometimes, late-season nor’easters have dumped inches of snow, while other years, heavy rainstorms brought flooding.
Conditions can change fast. If you’re organizing parades, festivals, or travel, you’ll want to prep for both wet and wintry weather. Keeping a close eye on the forecast helps you stay flexible.
Weather Patterns and Influences
Mid-March in Pennsylvania brings quick weather shifts. You might deal with sharp temperature swings, sudden rain or snow, and strong winds that can really mess with outdoor plans.
Impact of Cold Fronts
Cold fronts shape a lot of the weather in mid-March. When one rolls through, temperatures can drop 10–20°F in just a few hours. A mild afternoon can suddenly turn chilly.
These fronts bring unsettled weather. Rain showers are common, but sometimes you’ll get snow or sleet in colder years. Strong winds usually follow, making it feel even colder.
Travel can get tricky—cold fronts sometimes cause slippery roads or poor visibility if snow squalls develop. If you’re hosting something outside, you’ll want to plan for gusty winds and quick changes.
Typical cold front impacts in Pennsylvania around March 17:
- Temperature drop: 10–20°F in less than a day
- Precipitation: Rain, snow, or mixed events
- Wind: Gusts 20–35 mph, sometimes higher
These quick changes mean you should check the forecast, especially if you’re driving or spending a lot of time outdoors.
Transition from Winter to Spring
By mid-March, Pennsylvania sits in a weird spot between seasons. Average highs go from the low 40s in the north to the mid-50s in the south. Lows often hover near freezing, so frost and icy patches can still show up overnight.
Snow can stick around in higher elevations, but valleys warm up faster. Rain starts to outpace snow, but late-season snowfalls still happen, mostly in the north and west.
Every year feels a little different. One St. Patrick’s Day might bring sunshine and mild air, and the next could have snow showers and cold winds.
If you’re traveling or planning events, expect the unexpected. Bring layers, and be ready for anything from wet to dry. Flexibility is your best friend with Pennsylvania’s March weather.
Regional Differences Across Pennsylvania
Mid-March weather shifts a lot depending on where you are in the state. Elevation, distance from the coast, and local climate patterns all affect how warm, cold, wet, or snowy your day gets.
Eastern Pennsylvania Weather
In the east, including Philadelphia and the Lehigh Valley, you’ll usually find milder conditions. Daytime highs often reach the upper 40s °F, while nights can drop into the low 30s °F. Snow doesn’t show up as often by mid-March, but light rain showers happen frequently.
Lower elevation and the Atlantic Ocean’s influence keep temperatures more moderate. You might still need a jacket, but outdoor parades and festivals here usually don’t require heavy winter gear.
Typical Eastern PA conditions in mid-March:
- Highs: 46–50 °F
- Lows: 30–34 °F
- Precipitation: Rain more likely than snow
Central Pennsylvania Conditions
Central Pennsylvania—think Harrisburg or State College—sits up at a higher elevation, so you’ll get more variable weather than you might expect. Average highs usually land somewhere in the low to mid-40s °F.
Lows often dip into the upper 20s °F, and honestly, it’s anybody’s guess if you’ll see snow showers or just plain rain as March moves along. Rain starts to show up more often, but flurries can still surprise you.
Because the terrain rolls and dips, the weather can flip in a heartbeat. One town might get flurries, while just a few miles away, someone’s dealing with rain.
If you’re heading out to an event, just pack for both. You never really know what you’ll get.
Typical Central PA conditions in mid-March:
- Highs: 42–46 °F
- Lows: 27–30 °F
- Precipitation: Mix of rain and snow
Western Pennsylvania Climate
Western Pennsylvania, with places like Pittsburgh and Erie, usually stays colder and wetter this time of year. Highs hang out in the low 40s °F.
Overnight, lows fall into the mid-20s °F, so it’s not exactly spring yet. Snow’s still common, especially closer to Lake Erie, where lake-effect snow can sneak in.
You’ll see more steady precipitation out here, and the sky loves to stay cloudy. Expect the ground to be damp, and those winds? They’ll remind you it’s not quite spring.
Outdoor events feel a lot more like winter than you might hope.
Typical Western PA conditions in mid-March:
- Highs: 40–43 °F
- Lows: 24–27 °F
- Precipitation: Higher chance of snow, frequent clouds
Weather Considerations for St. Patrick’s Day Events
Mid-March in Pennsylvania usually brings cool air, leftover snow, and the occasional rain. Outdoor gatherings and travel plans can get tricky, so it really pays to keep the local climate in mind.
Outdoor Celebrations and Parades
St. Patrick’s Day parades in Pennsylvania happen right as spring’s trying to break through, so the weather can swing from the upper 30s to low 50s. Chilly winds, slick sidewalks, and a real chance of light rain or wet snow are all in play.
Layering is your friend here. The sun might feel nice, but step into the shade or stick around for the evening, and you’ll notice the chill.
Waterproof shoes are a smart choice, especially if there’s leftover slush or puddles from melting snow.
Organizers sometimes shuffle the schedule if rain gets heavy, but a little drizzle doesn’t usually stop the parade. Bring a small umbrella or a jacket with a hood—you’ll stay dry and won’t block anyone’s view.
Crowds can make things feel warmer, but if you’re standing still for a while, the cold creeps in. Toss in some hand warmers, gloves, or a hat, and you’ll thank yourself later.
Travel and Safety Tips
Driving around March 17 can get tricky. Sure, major snowstorms don’t usually hit by mid-March, but icy patches still pop up overnight or early in the morning.
You’ll probably notice more rain too, and wet roads with all that holiday traffic just mean more accident risks.
If you’re heading to events in cities like Philadelphia or Pittsburgh, give yourself some extra time. Parades often close streets, which sends drivers on detours, and parking fills up fast.
Public transit usually works well, but double-check the latest schedules since parade days can shuffle routes. Sometimes it’s just quicker to walk between venues, though if it’s wet out, those sidewalks get pretty slick.
Thinking about drinking during the festivities? Set up your ride ahead of time. Rideshare apps or a designated driver really are your best bet, especially with unpredictable weather and stricter enforcement on holiday weekends.