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

Nantucket, Massachusetts

Last updated: 10:57 AM CDT  ·  Refresh
23°C
Feels like 21°
Partly Cloudy
▲ 23°  /  ▼ 21°
Wind
15 mph SSE
Humidity
75%
Dew Point
17°
Pressure
29.97 inHg
Visibility
10 mi
UV Index
8.0
Cloud Cover
58%
Sunrise
5:25 AM
Sunset
8:07 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Nantucket is currently partly cloudy at 23°C. Precipitation is likely — peak probability 90% around 5 PM. Atmospheric instability is elevated (CAPE up to 531 J/kg) — isolated convective development possible. Sunrise: 5:25AM · Sunset: 8:07PM.

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
61 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
23°
19%
12 PM
23°
36%
1 PM
23°
34%
2 PM
23°
42%
3 PM
22°
73%
4 PM
22°
82%
5 PM
22°
90%
6 PM
22°
90%
7 PM
22°
85%
8 PM
22°
90%
9 PM
22°
76%
10 PM
22°
77%
11 PM
22°
90%
12 AM
22°
90%
1 AM
22°
85%
2 AM
22°
85%
3 AM
22°
90%
4 AM
22°
90%
5 AM
22°
80%
6 AM
22°
76%
7 AM
22°
76%
8 AM
23°
76%
9 AM
23°
72%
10 AM
23°
68%
7-Day Forecast
Today
23° 21°
Overcast with a 90% chance of rain.
Wed
23° 21°
Heavy Rain, 85% chance.
Thu
23° 18°
Rain, 64% chance.
Fri
21° 18°
Overcast with a 59% chance of rain.
Sat
21° 19°
Rain, 56% chance.
Sun
21° 19°
Rain, 61% chance.
Mon
23° 19°
Drizzle, 53% chance.
TimeTempConditionsPrecipWindHumidity
Now 23° Partly Cloudy 19% 15 mph SSE 75%
12 PM 23° Overcast 36% 17 mph SSE 74%
1 PM 23° Overcast 34% 18 mph SSE 76%
2 PM 23° Overcast 42% 20 mph SSE 80%
3 PM 22° Overcast 73% 21 mph SSE 85%
4 PM 22° Heavy Rain 82% 23 mph SSE 90%
5 PM 22° Overcast 90% 22 mph SSE 94%
6 PM 22° Heavy Rain 90% 22 mph SSE 95%
7 PM 22° Overcast 85% 21 mph S 96%
8 PM 22° Overcast 90% 22 mph S 96%
9 PM 22° Overcast 76% 25 mph S 96%
10 PM 22° Overcast 77% 26 mph S 96%
11 PM 22° Heavy Rain 90% 27 mph S 95%
12 AM 22° Heavy Rain 90% 27 mph SSW 95%
1 AM 22° Thunderstorm 85% 27 mph SSW 94%
2 AM 22° Heavy Rain 85% 26 mph SSW 94%
3 AM 22° Heavy Rain 90% 26 mph SSW 93%
4 AM 22° Heavy Rain 90% 25 mph S 95%
5 AM 22° Heavy Rain 80% 24 mph SSW 95%
6 AM 22° Heavy Rain 76% 24 mph SSW 95%
7 AM 22° Rain 76% 24 mph SSW 95%
8 AM 23° Rain 76% 24 mph SSW 95%
9 AM 23° Heavy Rain 72% 24 mph SSW 94%
10 AM 23° Heavy Rain 68% 25 mph SSW 94%
15-Day Forecast
Today
7/21
Overcast
90%
21°
23°
Wed
7/22
Heavy Rain
85%
21°
23°
Thu
7/23
Rain
64%
18°
23°
Fri
7/24
Overcast
59%
18°
21°
Sat
7/25
Rain
56%
19°
21°
Sun
7/26
Rain
61%
19°
21°
Mon
7/27
Drizzle
53%
19°
23°
Tue
7/28
Rain
69%
21°
23°
Wed
7/29
Drizzle
44%
21°
23°
Thu
7/30
Drizzle
44%
21°
22°
Fri
7/31
Drizzle
60%
21°
22°
Sat
8/1
Drizzle
60%
21°
22°
Sun
8/2
Drizzle
60%
21°
22°
Mon
8/3
Drizzle
60%
21°
22°
Tue
8/4
Drizzle
60%
21°
22°
61
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
61 AQI 14.3 µg/m³
O3
Ground-level ozone
37 AQI 40 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Wed 61 Moderate 37 61
Thu 39 Good 39 39
Fri 29 Good 29 20
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 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
SBCAPE0 J/kg
MLCAPE9 J/kg
MUCAPE0 J/kg
SBCIN-6964 J/kg
MLCIN0 J/kg
Lifted Index3.4
Kinematics
0–6 km Shear31 kt
0–1 km Shear12 kt
Eff. Shear—
0–1 km SRH-18
0–3 km SRH-47
Eff. SRH—
Storm Motion185° @ 33 kt
0–1 km EHI-0.0
Composite Parameters
Sig. Tornado-0.0
STP (eff)—
Supercell—
K-Index-16.1
Thermo & Levels
PWAT0.85 in
0–3 km LR4.3 °C/km
700–500 LR6.3 °C/km
Total Totals36.4
LCL936 hPa
LFC—
EL—
Freezing Lvl15,489 ft