Lehigh Valley PA Weather Forecast Explained: Why It’s So Hard to Predict

Waking up in the Lehigh Valley is a bit like playing a game of meteorological roulette. One minute you're scraping a thin sheet of annoying glaze off your windshield in Bethlehem, and twenty minutes later, you're driving through a perfectly dry, sunny stretch of Easton. It’s weird.

If you’ve lived here long enough, you know the drill. You don't just check the lehigh valley pa weather forecast once and call it a day; you check it while you’re putting on your boots, and then again before you actually open the front door. Today, Tuesday, January 13, 2026, is a prime example of that classic Valley indecision. We’re sitting at a fairly mild 43°F right now, but that "feels like" temp is hovering closer to 38°F thanks to a 9 mph breeze coming off the mountains.

It’s cloudy. Sorta grey. Basically, the standard January vibe for Allentown and the surrounding areas.

The Microclimate Chaos of the Valley

So, why is the lehigh valley pa weather forecast always such a moving target?

Geology. Honestly, it’s all about the dirt and the rocks. We are tucked between Blue Mountain to the north and South Mountain to our... well, south. This creates a literal bowl effect. When cold air sinks into this basin, it gets trapped. Meteorologists call this "cold air damming." For us, it just means that while Philadelphia is enjoying a nice 45-degree rain, we’re stuck with freezing rain that turns Route 22 into a skating rink.

What the numbers say for today

If you’re planning your evening, here’s the breakdown of what the sensors at Lehigh Valley International Airport (ABE) are screaming about:

• High: 49°F (reached earlier, though it feels colder now).
• Low: Dropping down to about 24°F tonight.
• Precipitation: There's a tiny 10% chance of a stray snow flurry or light rain, but don't hold your breath for a snow day.
• Humidity: 47%, which is actually pretty dry for us.

The gap between that 49-degree high and the 24-degree low is the real story. That’s a 25-degree swing in a matter of hours. If you leave your house in a light jacket this afternoon, you are going to be miserable by the time you're heading home from dinner.

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The "False Spring" and Other Local Lies

We get these weird warm spikes in January. It’s tempting to think winter is over. Don't do it. Historically, the coldest day of the year in the Lehigh Valley doesn’t even hit until January 29th. We have at least two more weeks of deep-freeze potential before we can even start talking about groundhogs and early blossoms.

The average high for January is usually around 37°F. So, hitting nearly 50°F today is a treat, but it’s an outlier. In 1932, the Valley hit a January record of nearly 40°F as an average for the whole month. On the flip side, 1918 saw an average of about 15.9°F. We are currently living in that middle ground where the weather can’t decide if it wants to be North Carolina or Quebec.

Why the wind feels different lately

Have you noticed it's been gustier? It’s not just in your head. Local chatter on places like Reddit suggests residents are feeling a shift. Data from 2024 and 2025 showed an increase in 40-50 mph gusts that seem to come out of nowhere. When that wind funnels through the "Wind Gap" (aptly named), it picks up speed and cuts right through your layers.

Survival Tips for the Next 48 Hours

Looking ahead at the lehigh valley pa weather forecast, Wednesday is going to be the real pivot point. We’re looking at a 50% chance of rain during the day, which likely turns into a messier 70% chance of "likely" rain and potentially some ice as the sun goes down and temps crash back into the 20s.

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1. Watch the transition: Wednesday night into Thursday morning is the danger zone. Any water on the road from Wednesday's "mild" rain will flash-freeze.
2. The Thursday "Crumble": Temperatures will actually fall throughout the day on Thursday. If it’s 35°F at 8:00 AM, expect it to be 28°F by lunch.
3. Layers are non-negotiable: Since we’re dealing with high humidity (often hitting 87% in the mornings), the cold feels "heavy." A windbreaker over a fleece is better than one giant parka.

What Most People Get Wrong

People think that because we aren't "up state" in the Poconos, we don't get real winter. Tell that to anyone who lived through the 1994 or 1996 blizzards. We are in a transition zone—specifically the border between humid continental and humid subtropical climates.

This means we get the worst of both worlds. We get the humidity of the south that makes the cold "bite" your skin, and the arctic blasts from the north that bring the snow. If you're looking at your weather app and it says "mostly cloudy," in the Lehigh Valley, that usually means a ceiling of grey that won't budge for three days.

Actionable Next Steps for Valley Residents

• Check the Dew Point: If you want to know if it's going to feel "raw" out there, look at the dew point rather than the temperature. Today it's around 22°F, which is crisp but not suffocating.
• Clear your gutters now: With rain expected Wednesday before a hard freeze on Thursday, any clogged gutters will turn into ice dams by Friday morning.
• Update your car kit: Make sure you have an actual ice scraper, not just a credit card. The freezing rain predicted for later this week is the "stuck-on" kind, not the fluffy stuff.

The Valley is beautiful, but it's temperamental. Stay ahead of the Wednesday night freeze-over, and keep an eye on those wind gusts if you're driving high-profile vehicles on I-78.