Philadelphia started the day on a crisp note, waking up to clear skies, calm air, and temperatures hovering around 45°F. Sunshine sticks around with mostly blue skies and a high near 66°F, as an easterly breeze gradually nudges up to about 10 mph this afternoon. Rain is basically off the table, but the weather story comes with two quick headlines: a brush with frost in some suburbs this morning and a sharp turn toward summer heat later this week.
Frost This Morning
A Frost Advisory was in place until 8 AM for parts of Berks, western Chester, and western Montgomery counties, where temperatures dipped into the low to mid 30s and could nip at tender plants, according to the National Weather Service Mount Holly. Patchy frost was also on the table for higher elevations and the Lehigh Valley, so gardeners on the outer edges of the metro may want to scan the garden for frosty leaves before calling it safe.
Warm-Up Later This Week
That brief flirtation with frost does not last long. Forecasters at the National Weather Service expect temperatures to jump into the 80s on Monday, with mid 80s likely Tuesday and some spots along the I-95 corridor potentially cracking 90°F on Wednesday and Thursday. For a few neighborhoods, that could be the first 90-degree mark of the season. The warmest readings should be found in interior parts of the city, while the riverfront and the shore hang onto cooler air. Most days look dry with low humidity, which means drought and fire-spread concerns are not going anywhere; see how a bone-dry breeze is putting Philly on edge for fast-moving fires for more local context.
Boaters
Out on the water, boaters should prepare for a Small Craft Advisory along the Atlantic coastal waters on Monday as seas build to around 5 to 6 feet and southerly winds gust to roughly 25 knots. Delaware Bay is expected to stay below advisory levels, but anyone with plans on the boat should still check the latest marine forecast and be ready for choppy conditions and punchy gusts.
What To Know
If you can, cover or bring in tender plants early this morning, then dress in layers so you are comfortable from chilly sunrise to mild afternoon. Looking ahead to early next week, keep an eye on the forecast if you have outdoor plans. If those 90s do show up, water, shade, and pacing yourself will matter more than they have so far this year.
