On Monday, April 27, 2026, Philadelphia rolled out of bed to clear skies and a sharp chill, with temperatures in the low 40s and sheltered spots dipping into the upper 30s. That was just cold enough to paint pockets of frost and patchy fog across outlying neighborhoods. The payoff comes later, as sunshine builds and nudges afternoon highs into the upper 60s to around 70°F with light winds for a calm, comfortable finish before a wetter stretch muscles in midweek.
Morning Frost And Patchy Fog
A Frost Advisory is posted for parts of southeastern Pennsylvania and southern New Jersey until 8 a.m. Monday, April 27. Clear skies and light overnight winds helped temperatures slide into the low 40s, with mid and upper 30s in sheltered spots. That has meant frost on lawns and exposed plants. Gardeners are urged to cover tender vegetation, and drivers should keep an eye out for potentially slick patches on bridges and overpasses. These details come from the National Weather Service Mount Holly.
Sunny Warm-Up Today
Once the frost and fog fade, mostly sunny skies will take over with a high near 70°F. Northeast winds around 0 to 5 mph will gradually ease around to the east this afternoon. With low afternoon humidity, lunch outdoors or a quick park break should feel pretty ideal. By Monday night, temperatures slide back into the mid 40s under mostly clear skies.
Rain Returns Midweek
A weak frontal boundary brings a chance of light rain Tuesday, more of a nuisance than a washout. The real weather maker arrives late Wednesday into early Thursday, when a stronger system is expected to deliver more widespread showers and isolated thunderstorms. Forecast rainfall totals from Wednesday evening through Thursday morning are in the neighborhood of 0.75 to 1.00 inches across much of the region, so the Wednesday evening commute is looking soggy. Forecasters at the National Weather Service Mount Holly are keeping tabs on the timing and exact amounts.
On The Water
Offshore waters remain under a Small Craft Advisory through about 6 p.m. Monday, with seas running around 5 to 6 feet this morning before slowly easing later in the day. Recreational boaters and ferry riders should be ready for choppy crossings and check marine alerts before casting off.
What To Bring
Cover up those tender plants until the morning advisory expires, and give yourself a few extra minutes on the drive in case patchy fog lingers. A light jacket will come in handy today, and you will want an umbrella in the mix for Wednesday night if you have late plans.
Previous Coverage
For a look back at the recent raw setup and blustery conditions, see raw rain and gritty fog, which breaks down Sunday’s unsettled stretch and how it sets the stage for this week.
