High Surf Advisory — Southern Bristol, MA, Southern Plymouth, MA, Barnstable, MA, Dukes, MA, Nantucket, MA, Washington, RI, Newport, RI, Block Island, RI 7:00 PM

Barnstable County, Massachusetts, United States

Last updated: 10:56 AM CDT  ·  Refresh
24°C
Feels like 22°
Overcast
▲ 25°  /  ▼ 20°
Wind
13 mph SSE
Humidity
63%
Dew Point
16°
Pressure
29.94 inHg
Visibility
10 mi
UV Index
5.0
Cloud Cover
85%
Sunrise
5:25 AM
Sunset
8:09 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Barnstable County is currently overcast at 24°C. Precipitation is likely — peak probability 90% around 5 PM. Atmospheric instability is elevated (CAPE up to 621 J/kg) — isolated convective development possible. Sunrise: 5:25AM · Sunset: 8:09PM.

Alerts

High Surf Advisory
Southern Bristol, MA, Southern Plymouth, MA, Barnstable, MA, Dukes, MA, Nantucket, MA, Washington, RI, Newport, RI, Block Island, RI
Expires 7:00 PM
63 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
24°
24%
12 PM
25°
48%
1 PM
25°
41%
2 PM
24°
54%
3 PM
23°
71%
4 PM
23°
86%
5 PM
23°
90%
6 PM
23°
90%
7 PM
23°
90%
8 PM
23°
90%
9 PM
23°
90%
10 PM
23°
90%
11 PM
23°
90%
12 AM
22°
85%
1 AM
22°
85%
2 AM
22°
85%
3 AM
22°
86%
4 AM
22°
86%
5 AM
22°
86%
6 AM
22°
78%
7 AM
22°
76%
8 AM
23°
76%
9 AM
24°
71%
10 AM
24°
72%
7-Day Forecast
Today
25° 20°
Overcast with a 90% chance of rain.
Wed
25° 19°
Rain, 86% chance.
Thu
22° 17°
Mostly Cloudy with a 35% chance of rain.
Fri
21° 17°
Mostly Cloudy.
Sat
21° 17°
Clear with a 21% chance of rain.
Sun
21° 18°
Clear with a 21% chance of rain.
Mon
24° 19°
Clear with a 24% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 24° Overcast 24% 13 mph SSE 63%
12 PM 25° Overcast 48% 15 mph SSE 63%
1 PM 25° Overcast 41% 16 mph SSE 65%
2 PM 24° Overcast 54% 16 mph SSE 72%
3 PM 23° Overcast 71% 17 mph SSE 79%
4 PM 23° Heavy Rain 86% 18 mph SSE 88%
5 PM 23° Overcast 90% 18 mph SSE 92%
6 PM 23° Heavy Rain 90% 17 mph SSE 94%
7 PM 23° Overcast 90% 17 mph S 95%
8 PM 23° Overcast 90% 18 mph S 95%
9 PM 23° Heavy Rain 90% 19 mph S 95%
10 PM 23° Overcast 90% 20 mph S 95%
11 PM 23° Heavy Rain 90% 19 mph S 94%
12 AM 22° Heavy Rain 85% 19 mph SSW 95%
1 AM 22° Thunderstorm 85% 17 mph SSW 95%
2 AM 22° Rain 85% 17 mph SSW 94%
3 AM 22° Rain 86% 17 mph SSW 94%
4 AM 22° Rain 86% 17 mph SSW 94%
5 AM 22° Rain 86% 17 mph SSW 93%
6 AM 22° Rain 78% 17 mph SSW 94%
7 AM 22° Rain 76% 17 mph SSW 94%
8 AM 23° Overcast 76% 17 mph SSW 91%
9 AM 24° Overcast 71% 18 mph SSW 88%
10 AM 24° Overcast 72% 18 mph SSW 85%
15-Day Forecast
Today
7/21
Overcast
90%
20°
25°
Wed
7/22
Rain
86%
19°
25°
Thu
7/23
Mostly Cloudy
35%
17°
22°
Fri
7/24
Mostly Cloudy
14%
17°
21°
Sat
7/25
Clear
21%
17°
21°
Sun
7/26
Clear
21%
18°
21°
Mon
7/27
Clear
24%
19°
24°
Tue
7/28
Rain
69%
20°
24°
Wed
7/29
Drizzle
44%
19°
25°
Thu
7/30
Clear
21%
19°
24°
Fri
7/31
Drizzle
60%
19°
22°
Sat
8/1
Drizzle
60%
20°
22°
Sun
8/2
Drizzle
60%
20°
23°
Mon
8/3
Drizzle
60%
20°
23°
Tue
8/4
Drizzle
60%
20°
23°
63
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
63 AQI 15.4 µg/m³
O3
Ground-level ozone
39 AQI 42 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Wed 63 Moderate 39 63
Thu 45 Good 45 37
Fri 33 Good 33 23
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 LCLLFCEL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid Tue Jul 21, 14:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE3 J/kg
MLCAPE6 J/kg
MUCAPE3 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index3.4
Kinematics
0–6 km Shear32 kt
0–1 km Shear10 kt
Eff. Shear—
0–1 km SRH-11
0–3 km SRH-45
Eff. SRH—
Storm Motion182° @ 33 kt
0–1 km EHI-0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)—
Supercell—
K-Index-16.0
Thermo & Levels
PWAT0.84 in
0–3 km LR4.9 °C/km
700–500 LR6.3 °C/km
Total Totals34.8
LCL906 hPa
LFC1014 hPa
EL975 hPa
Freezing Lvl15,282 ft