Severe Thunderstorm Watch 11:00 PM Areal Flood Watch 1:00 AM

Frederick County, Maryland, United States

Last updated: 10:30 PM CDT  ·  Refresh
21°C
Feels like 23°
Mostly Cloudy
▲ 29°  /  ▼ 19°
Wind
6 mph SSW
Humidity
94%
Dew Point
20°
Pressure
29.29 inHg
Visibility
10 mi
UV Index
0.0
Cloud Cover
80%
Sunrise
5:59 AM
Sunset
8:31 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Frederick County is currently mostly cloudy at 21°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 862 J/kg) — isolated convective development possible. Sunrise: 5:59AM · Sunset: 8:31PM.

Alerts

Severe Thunderstorm Watch
Expires 11:00 PM
Areal Flood Watch
Expires 1:00 AM
52 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
21°
25%
12 AM
21°
23%
1 AM
21°
15%
2 AM
21°
9%
3 AM
21°
13%
4 AM
21°
15%
5 AM
19°
20%
6 AM
20°
11%
7 AM
21°
8%
8 AM
22°
11%
9 AM
23°
8%
10 AM
25°
13%
11 AM
26°
13%
12 PM
26°
8%
1 PM
27°
8%
2 PM
28°
5%
3 PM
27°
5%
4 PM
27°
5%
5 PM
27°
3%
6 PM
26°
3%
7 PM
25°
3%
8 PM
24°
3%
9 PM
23°
3%
10 PM
22°
3%
7-Day Forecast
Tonight
29° 19°
Mostly Cloudy with a 25% chance of rain.
Wed
28° 17°
Mostly Clear with a 20% chance of rain.
Thu
27° 14°
Clear.
Fri
27° 14°
Overcast.
Sat
27° 16°
Clear.
Sun
30° 17°
Rain, 70% chance.
Mon
32° 19°
Rain, 71% chance.
TimeTempConditionsPrecipWindHumidity
Now 21° Mostly Cloudy 25% 6 mph SSW 94%
12 AM 21° Mostly Cloudy 23% 7 mph SSW 94%
1 AM 21° Mostly Cloudy 15% 7 mph SSW 95%
2 AM 21° Partly Cloudy 9% 6 mph SSW 96%
3 AM 21° Partly Cloudy 13% 6 mph SSW 96%
4 AM 21° Partly Cloudy 15% 5 mph SSW 96%
5 AM 19° Partly Cloudy 20% 5 mph SW 96%
6 AM 20° Mostly Clear 11% 5 mph SW 94%
7 AM 21° Mostly Clear 8% 6 mph WSW 93%
8 AM 22° Mostly Clear 11% 7 mph WSW 87%
9 AM 23° Mostly Clear 8% 8 mph W 79%
10 AM 25° Mostly Clear 13% 10 mph W 70%
11 AM 26° Mostly Clear 13% 11 mph W 64%
12 PM 26° Mostly Clear 8% 11 mph W 60%
1 PM 27° Mostly Clear 8% 11 mph W 57%
2 PM 28° Mostly Clear 5% 11 mph W 55%
3 PM 27° Mostly Clear 5% 11 mph W 55%
4 PM 27° Mostly Clear 5% 11 mph WNW 54%
5 PM 27° Mostly Clear 3% 10 mph WNW 56%
6 PM 26° Clear 3% 9 mph WNW 59%
7 PM 25° Clear 3% 8 mph NW 62%
8 PM 24° Clear 3% 8 mph NW 64%
9 PM 23° Mostly Clear 3% 8 mph NW 64%
10 PM 22° Mostly Clear 3% 8 mph NNW 64%
15-Day Forecast
Today
7/21
Mostly Cloudy
25%
19°
29°
Wed
7/22
Mostly Clear
20%
17°
28°
Thu
7/23
Clear
3%
14°
27°
Fri
7/24
Overcast
14%
14°
27°
Sat
7/25
Clear
8%
16°
27°
Sun
7/26
Rain
70%
17°
30°
Mon
7/27
Rain
71%
19°
32°
Tue
7/28
Thunderstorm
63%
17°
34°
Wed
7/29
Drizzle
44%
16°
31°
Thu
7/30
Drizzle
44%
16°
29°
Fri
7/31
Drizzle
60%
16°
29°
Sat
8/1
Drizzle
60%
17°
29°
Sun
8/2
Drizzle
60%
17°
30°
Mon
8/3
Drizzle
60%
18°
31°
Tue
8/4
Drizzle
60%
19°
32°
52
Moderate
U.S. Air Quality Index · Dominant: PM2.5
50 100 150 200

Air quality is acceptable. Unusually sensitive people should consider limiting prolonged outdoor exertion.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
Dominant
52 AQI 9.6 µg/m³
O3
Ground-level ozone
36 AQI 40 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 52 Moderate 36 52
Thu 40 Good 40 16
Fri 40 Good 40 25
About the Air Quality Index
0–50 Good
51–100 Moderate
101–150 Unhealthy for Sensitive Groups
151–200 Unhealthy
201–300 Very Unhealthy
301–500 Hazardous

The U.S. AQI runs 0–500. The overall value equals the highest individual pollutant sub-index, and the dominant pollutant is the one driving it. PM2.5 (fine particles) is reported in µg/m³ and ozone (O3) in ppb. Forecast source: NWS NAQFC.

1000850700500400300250200150100 -40-30-20-10010203040 0.41247101624 LCL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid Wed Jul 22, 02:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 60 70 80 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE0 J/kg
MLCAPE51 J/kg
MUCAPE273 J/kg
SBCIN-5477 J/kg
MLCIN0 J/kg
Lifted Index0.3
Kinematics
0–6 km Shear34 kt
0–1 km Shear38 kt
Eff. Shear10 kt
0–1 km SRH-18
0–3 km SRH19
Eff. SRH22
Storm Motion239° @ 37 kt
0–1 km EHI-0.0
Composite Parameters
Sig. Tornado-0.0
STP (eff)0.0
Supercell0.0
K-Index33.7
Thermo & Levels
PWAT1.79 in
0–3 km LR4.1 °C/km
700–500 LR6.1 °C/km
Total Totals47.2
LCL973 hPa
LFC—
EL—
Freezing Lvl14,442 ft