Philadelphia is flirting with something that feels downright balmy this week: daytime highs nudging close to 40 degrees, starting Tuesday. Cue the hopeful looks at dirty snowbanks, the optimistic Instagram stories, the “maybe I don’t need boots” energy.
But if you’re counting on this brief warm-up to wipe winter clean, meteorologists have some bad news. Most of that snow and ice isn’t going anywhere — at least not in the way residents might wish.
40° isn’t that warm — especially for snow that’s been sitting awhile
Snow doesn’t melt instantly the moment the thermometer hits 32°. Once it’s been compacted by plows, cars, and foot traffic, it becomes denser — more ice than fluff. That packed snow needs sustained warmth, not a few afternoon hours hovering near 40, to really break down.
Overnight lows matter, too. When temperatures dip back below freezing after sunset, any daytime melting slows or refreezes, locking that ice right back in place.
The sun angle is still working against us
Even on a “warm” February or early-March day, the sun is weaker than people expect. Shorter days and a lower sun angle mean less solar energy reaching sidewalks, streets, and shaded corners — the exact places where snow lingers longest.
That’s why south-facing lawns might show grass first, while north-side stoops and alleyways stay icy for days. Winter knows where to hide.
Salt can only do so much
Road crews and residents have already put down plenty of salt, but salt’s effectiveness drops as temperatures fall — and it doesn’t magically erase thick ice. Instead, it often creates a thin layer of meltwater on top, which can refreeze overnight into that extra-slick sheen everyone loves to hate.
Translation: the slush may look promising at 3 p.m., but it’s plotting its comeback by morning commute time.
Snowbanks melt from the edges, not the middle
Those gray, gritty piles along curbs are basically mini glaciers. They melt slowly from the outside in, which means days of runoff puddles — and nights of refrozen ice — before they actually disappear.
So yes, you might see some shrinking. But a full snowbank collapse? That takes days of temperatures well above freezing, not a brief flirtation with spring.
The takeaway
This week’s near-40° weather will soften things, not solve them. Expect patchy melting, soggy corners, and icy leftovers — especially in the morning and in shaded spots.
But there is hope. Next Monday is the first forecast night where temperatures are expected to stay north of freezing since, oh, 2016 (OK, January), which is what we actually need to stop the melt-and-refreeze cycle. It might even rain, which would help, too. The two days after that look similar temp-wise, if drier.
So one more week and maybe you can bravely cross a street again. Believe it, Philadelphia!
