The Coolest Night of the Season So Far — Clear Skies, Patchy 30s Inland

High pressure is sliding offshore tonight, but not before it delivers the coolest, clearest night of the season so far across Maryland. NWS Baltimore/Washington (2:47 PM issuance) and NWS Wakefield (2:44 PM) both flag radiational cooling under light winds and a mostly clear sky as the story overnight, with some interior valleys flirting with the upper 30s. No hazardous weather is expected per the Baltimore/Washington Hazardous Weather Outlook issued at 4:07 PM — this is about as clean a forecast as you’ll see this fall.

Timing Tonight

• Evening (6–9 PM): Skies clear out fully as the sun sets; winds go light and variable. Comfortable for any outdoor plans — jacket weather by dark.
• Late evening into midnight: Temperatures fall quickly under the clear sky and calm winds — classic radiational cooling setup. Western Maryland valleys and typically cool low-lying spots start dropping fast.
• Overnight (2 AM–sunrise): Coldest point of the night, right around or just before dawn. Patchy frost is plausible in the usual cold pockets of Garrett and far western Allegany counties, though MDWA notes no formal Frost Advisory has been issued for Maryland tonight.
• Sunrise Wednesday: High pressure begins shifting offshore, winds turn southerly, and the warm-up starts almost immediately after sunrise.

Region by Region

Western Maryland

Garrett County (Deep Creek/Oakland): Clear and calm, dropping to around 42° — the coldest spot on the map tonight. With light south winds near 5 mph and a dry airmass, some of the usual frost hollows around Deep Creek and the high valleys could see patches of frost by early morning. Grab a blanket if you’re camping up there.

Allegany County (Cumberland): Clear skies, light south winds around 2 mph, low near 44°. A crisp, quiet night for the Narrows and the C&O Canal towpath — bundle up if you’re out late.

Northern & Central Maryland

Washington County (Hagerstown): Clear, light south winds near 5 mph, low around 44°. A classic fall night in the Cumberland Valley — stargazing conditions are excellent.

Frederick County: Clear and calm, low near 45°. Monocacy Valley farmland could see a touch of ground fog develop toward dawn given the calm winds and cooling.

Carroll County: Shares the Frederick gridpoint — clear, low near 45°, light winds. Comfortable sleeping-with-the-window-open weather if you like it crisp.

Baltimore Metro

Baltimore City & County: Clear skies, light southwest winds near 3 mph, low around 50°. Urban heat island keeps the city a touch milder than the surrounding counties.

Harford County: Shares the Baltimore/Central MD zone — clear, low near 50°, calm winds. Pleasant, quiet night from Bel Air to Havre de Grace.

Howard County: Same zone — clear and low around 50°. A good night for the Columbia lakefronts to look still and glassy.

Anne Arundel County: Clear, low near 50°, with light winds off the Bay keeping things a degree or two milder near the water in Annapolis and along the Severn.

DC Suburbs

Montgomery County (Silver Spring): Clear, light southeast winds near 3 mph, low around 47°. A refreshing night after a sunny, cool afternoon.

Prince George’s County: Shares the Silver Spring gridpoint — clear, low near 47°. College Park and points south stay comfortably cool overnight.

Southern Maryland

Charles County: Clear, light southeast winds near 5 mph, low around 48°.

Calvert County: Same zone (Prince Frederick gridpoint) — clear, low near 48°, with the Bay keeping the Calvert cliffs area a touch milder than inland spots.

St. Mary’s County: Clear and calm, low near 48°. A tranquil night along the Patuxent and Potomac shorelines.

Upper Eastern Shore

Cecil County: Clear, light south winds, low in the mid 40s — closely tracking the Easton gridpoint value of 45°.

Kent County: Clear skies, low around 45°, calm and quiet along the upper Chesapeake.

Queen Anne’s County: Same zone — clear, low near 45°. Good night for a late walk along the Chester River.

Talbot County: Clear, low around 45°, light south winds near 5 mph. St. Michaels and Easton stay crisp but comfortable.

Caroline County: Shares the Easton gridpoint — clear, low near 45°, inland spots possibly dipping a touch cooler in low-lying farmland.

Lower Eastern Shore

Dorchester County: Clear, calm winds, low around 44° — tracking the Salisbury gridpoint.

Wicomico County (Salisbury): Clear skies, light east winds near 2 mph, low near 44°.

Somerset County: Same zone — clear, low around 44°, with marsh areas near Crisfield possibly seeing some patchy fog form toward dawn.

Ocean City & the Coast

Worcester County / Ocean City: Clear skies, light northwest winds 1–5 mph, low around 47° — the mildest overnight low on the Maryland map thanks to the moderating ocean influence. Surf is small, running 2 to 3 feet, with a low rip current risk per NWS Wakefield’s surf zone forecast. Water temperature holds near 70°. High tide at the Ocean City Fishing Pier was at 5:01 PM; the next high tide comes late tomorrow afternoon near 5:53 PM. A beautifully calm beach night if you’re staying nearby.

Active Hazards

There are currently no active watches, warnings, or advisories for Maryland. The Baltimore/Washington Hazardous Weather Outlook, issued 4:07 PM, explicitly states no hazardous weather is expected tonight across the Chesapeake Bay, tidal Potomac, and I-95 corridor zones. Note: NWS Mount Holly has a Frost Advisory in effect tonight for the Poconos and Sussex County, NJ — that is outside Maryland and does not apply here, but it underscores just how efficiently this airmass is cooling things down regionally.

Severe Weather & Flooding

None expected. This is a dry, stable, high-pressure-driven night from the mountains to the coast. The next weather-maker of any real consequence — a plume of Gulf moisture tied to a developing system NHC is watching in the southwestern Gulf (AL92) — stays well out beyond this forecast period, with potential impacts not arriving until late this weekend into early next week at the earliest. Confidence on that system’s track remains low; NWS Baltimore/Washington outlined four very different scenarios ranging from a notable rain event to essentially nothing reaching Maryland. We’ll keep watching it.

Winds & Chesapeake Bay

Winds tonight are light across the board — generally south to southeast at 2 to 5 mph, occasionally calm in the Bay-side counties. No marine hazards are in effect tonight. Looking ahead, NWS Baltimore/Washington notes winds will strengthen out of the south Wednesday, with marginal small craft conditions possible Wednesday evening on the Bay — something boaters should keep an eye on, though nothing is in effect as of this writing.

Overnight Lows by Zone

Looking Ahead

Wednesday: A big warm-up as winds turn southerly and high pressure shifts offshore. Highs climb into the 70s across most of the state — around 76° in Cumberland and Hagerstown, near 72–74° for the I-95 corridor and Frederick/Carroll, upper 60s on the Eastern Shore (67° Easton, 69° Salisbury), and Ocean City staying cooler at 65° thanks to the ocean influence. Sunny throughout, with no rain chances anywhere.

Thursday: Even warmer, with highs approaching 80° inland — 76–79° for Baltimore, DC suburbs, Southern Maryland, and the Eastern Shore, mid-70s in Cumberland and Hagerstown. This comes just ahead of a dry cold front that crosses Thursday night, knocking temperatures back down to more seasonal levels for Friday and Saturday. Still dry through Saturday across the board.

Beyond that, all eyes are on AL92 in the Gulf and how it evolves — any rain chances wouldn’t arrive until Sunday at the earliest, and confidence remains low on amounts and placement. We’ll have updates as the picture sharpens.

Data: NWS Baltimore/Washington, Mount Holly & Wakefield.
MD Weather Alerts — your director’s-cut forecast for every corner of Maryland. Sleep well, stay warm, and we’ll see you with the morning update.