Today | Weather | Wednesday, May 20, 2026
Active Weather Warnings

Weather in Frederick, Maryland

05:50 PM
Now
Stormy Weather
72° F
Feels Like 75°
Precipitation 63 %
Wind 7 mph
UV Index (0 - 11+) 0
Humidity 100 %
Today
Sunny with a Chance of Thunderstorms
Day 93°
Night 55°
Precipitation 90 %
Wind 7 mph
UV Index (0 - 11+) 10

Warning: High UV Index Today: 10

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

Frederick Weather Forecast Updated

Last updated on

Air Quality in Frederick

NOW
43 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.12 µg/m³
PM10 1.63 µg/m³
O3 0.046 ppm
NO2 0.7 ppb
SO2 0.1 ppb
CO 0.09 ppm
NH3 1.27 µg/m³
NO 0.03 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.51.12 µg/m³
PM101.63 µg/m³
O390.43 µg/m³
NO21.23 µg/m³
SO20.22 µg/m³
CO108.03 µg/m³
NH31.27 µg/m³
NO0.03 µg/m³

Weather Alerts and Warnings for Frederick

Severe Future Possible

Severe Thunderstorm Watch

Severe Thunderstorm Watch issued May 20 at 12:39PM EDT until May 20 at 8:00PM EDT by NWS Baltimore MD/Washington DC
May 20, 12:39 PM May 20, 8:00 PM
THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
234 IN EFFECT UNTIL 8 PM EDT THIS EVENING FOR THE FOLLOWING AREAS

THE DISTRICT OF COLUMBIA

IN MARYLAND THIS WATCH INCLUDES 13 COUNTIES

IN CENTRAL MARYLAND

ANNE ARUNDEL HOWARD
MONTGOMERY
PRINCE GEORGES

IN NORTH CENTRAL MARYLAND

CARROLL FREDERICK
WASHINGTON

IN NORTHEAST MARYLAND

CECIL

IN NORTHERN MARYLAND

BALTIMORE
BALTIMORE CITY
HARFORD

IN WESTERN MARYLAND

ALLEGANY GARRETT

IN VIRGINIA THIS WATCH INCLUDES 22 COUNTIES

IN CENTRAL VIRGINIA

GREENE

IN NORTHERN VIRGINIA

ARLINGTON
CITY OF ALEXANDRIA
CITY OF FAIRFAX
CITY OF FALLS CHURCH
CITY OF MANASSAS
CITY OF MANASSAS PARK
CULPEPER FAIRFAX
FAUQUIER LOUDOUN
PRINCE WILLIAM

IN NORTHWEST VIRGINIA

CITY OF WINCHESTER
CLARKE FREDERICK
MADISON PAGE
RAPPAHANNOCK
SHENANDOAH WARREN

IN WESTERN VIRGINIA

CITY OF HARRISONBURG
ROCKINGHAM

IN WEST VIRGINIA THIS WATCH INCLUDES 8 COUNTIES

IN EASTERN WEST VIRGINIA

GRANT HAMPSHIRE
HARDY MINERAL
PENDLETON

IN PANHANDLE WEST VIRGINIA

BERKELEY JEFFERSON
MORGAN

THIS INCLUDES THE CITIES OF ABERDEEN, ABINGDON, ADAMS MORGAN,
ADEN, AIRLIE, ALBIN, ALEXANDRIA, ALONZAVILLE, ANDORA, ANNANDALE,
ANNAPOLIS, ANTIOCH, APPLETON, ARCO, ARLINGTON, ARNOLD, BAKERTON,
BALLENGER CREEK, BALLSTON, BALTIMORE, BARCROFT, BARKSDALE,
BAY VIEW, BEAN SETTLEMENT, BENTONVILLE, BERKELEY SPGS,
BERRYVILLE, BERRYVILLE, BETHEL, BETHESDA, BLAKE, BLOOMERY,
BOHEMIAS MILLS, BOWIE, BOYDS, BRADY, BRAKE, BRANDYWINE,
BRANTWOOD, BUCKEYSTOWN, BUCKTON, BURKE, BYNUM, CABINS, CARDOVA,
CATALPA, CATONSVILLE, CEDAR GROVE, CEDARVILLE, CHANTILLY,
CHARLES TOWN, CHERRYDALE, CHESTER GAP, CLARKSVILLE, CLARY,
CLINTON, COLLEGE PARK, COLUMBIA, COMPTON, COUNTRYSIDE, CULPEPER,
CUMBERLAND, DALE CITY, DULLES INTERNATIONAL AIRPORT, DUNDALK,
EDGEWOOD, ELDERSBURG, ELLERSLIE, ESSEX, FAIRFAX, FAIRFAX STATION,
FAIRVIEW, FALLS CHURCH, FELLS POINT, FISHER, FIVE FORKS,
FORDSVILLE, FORT ASHBY, FOUR CORNERS, FRANKLIN, FREDERICK,
FRENCHBURG, FRONT ROYAL, FROSTBURG, GAINESBORO, GAITHERSBURG,
GAMBER, GERMANTOWN, GLEEDSVILLE, GLEN BURNIE, GLEN ECHO,
GLENMONT, GRANTSVILLE, GREENBELT, HAGERSTOWN, HALFWAY, HAMBURG,
HANCOCK, HARFORD FURNACE, HARRISONBURG, HAWKINSTOWN, HEADSVILLE,
HICKORY, HISTORIC ELLICOTT CITY, HOWELLSVILLE, INDEPENDENT HILL,
KEYSER, KIMBALL, KLINE GAP, LAKE RIDGE, LANDES, LANGLEY,
LEESBURG, LINVILLE, LUCKETTS, LURAY, MADISON MILLS, MAGNOLIA,
MAGNOLIA, MANASSAS, MANASSAS PARK, MARTINSBURG, MASONVILLE,
MCCOOLE, MCLEAN, MCNEILL, MIDDLEWAY, MILLVILLE, MONTCLAIR,
MONTPELIER, MOOREFIELD, MOUNT CLIFTON, MOUNT JACKSON,
MOUNTAIN LAKE PARK, NEW CREEK, OAK FLAT, OAK GROVE, OAKLAND,
PARK HEIGHTS, PARK MILLS, PARKVILLE, PAW PAW, PETERSBURG, POINTS,
PURGITSVILLE, RANDALLSTOWN, RANSON, RAPIDAN, RAWLINGS,
REAGAN NATIONAL AIRPORT, RESTON, REVA, RIDGEVILLE, RIDGEWAY,
RILEYVILLE, RIVERCREST, RIVERTON, ROMNEY, ROSSLYN, RUDDLE,
RUSSELLDALE, SEVERN, SEVERNA PARK, SEYMOURVILLE, SHADY GROVE,
SHADY GROVE, SHENANDOAH JUNCTION, SILVER SPRING, SIMPSONVILLE,
SKYLAND, SMITH CROSSROADS, SOUTH GATE, SPRINGFIELD,
STERLING PARK, STEVENSBURG, STRASBURG, STRINGTOWN, SUGAR GROVE,
SUITLAND-SILVER HILL, TANTALLON, THREE CHURCHES, TOWSON,
TURNBULL, TWYMANS MILL, WAPOCOMO, WARRENTON, WASHINGTON, WELTON,
WESTMINSTER, WINCHESTER, WINSTON, WOODBRIDGE, WOODLAWN,
WOODSTOCK, AND WOODSTOCK.
Updated: May 20, 4:38 PM Source: NWS Alert