Grand Isle, ME Weather Forecast

Local 7-day forecast

71°
F

Mostly Cloudy then Widespread Showers And Thunderstorms

Track current conditions, temperature changes, wind, and the full daily outlook for Grand Isle, ME in one place.

Saturday, July 18, 2026
Wind: 5 to 9 mph S
Saturday

A chance of rain showers between noon and 5pm, then widespread showers and thunderstorms. Mostly cloudy. High near 71, with temperatures falling to around 64 in the afternoon. South wind 5 to 9 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.

Local 7-day forecast

Local Weather Overview

This forecast page for Grand Isle, ME is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Jul 17, 2026 6:29 PM EDT.

The active forecast window currently covers Jul 18 to Jul 23, 2026 for Grand Isle, ME.

Page Snapshot

Page focus
city weather
Forecast window
Jul 18 to Jul 23, 2026
Latest sync
Jul 17, 2026 6:29 PM EDT
Forecast office
CAR
Source
NOAA / NWS
Next High
71°F
Saturday
Next Low
55°F
Saturday Night
Rain Outlook
9
Periods mentioning precipitation
Windiest
12 to 16 mph
Sunday

Daily Outlook

Today
Jul 18
Mostly Cloudy then Widespread Showers And Thunderstorms
71 °F
/ 55°F
Wind 5 to 9 mph
Sun
Jul 19
Rain Showers Likely
68 °F
/ 52°F
Wind 12 to 16 mph
Mon
Jul 20
Sunny
73 °F
/ 54°F
Wind 7 to 10 mph
Tue
Jul 21
Mostly Sunny
78 °F
/ 58°F
Wind 7 to 15 mph
Wed
Jul 22
Showers And Thunderstorms
75 °F
/ 59°F
Wind 12 mph
Thu
Jul 23
Chance Rain Showers
74 °F
/ 56°F
Wind 7 to 10 mph

This Week in Grand Isle

Tuesday looks like the warmest upcoming period in Grand Isle at 78 degrees F.

Sunday Night is the coolest period ahead with temperatures near 52 degrees F.

The strongest winds are forecast for Sunday at about 12 to 16 mph W.

Precipitation is mentioned in 9 upcoming forecast periods.

Forecast Details

Last updated
Jul 17, 2026 6:29 PM EDT
Coverage
6 days
Time zone
America/New_York
Forecast office
CAR
Radar station
KCBW

Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.

Open NOAA source

Extended Forecast

Saturday Night
Jul 18
55°F
Showers And Thunderstorms
10 mph S

Showers and thunderstorms before 10pm, then patchy smoke and showers and thunderstorms between 10pm and 4am, then patchy smoke and scattered rain showers. Cloudy, with a low around 55. South wind around 10 mph, with gusts as high as 22 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

Sunday
Jul 19
68°F
Rain Showers Likely
12 to 16 mph W

Rain showers likely before 2pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 68. West wind 12 to 16 mph, with gusts as high as 29 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.

Sunday Night
Jul 19
52°F
Slight Chance Showers And Thunderstorms then Partly Cloudy
10 to 14 mph W

A slight chance of showers and thunderstorms before 7pm. Partly cloudy, with a low around 52. West wind 10 to 14 mph, with gusts as high as 25 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

Monday
Jul 20
73°F
Sunny
7 to 10 mph W

Sunny, with a high near 73. West wind 7 to 10 mph.

Monday Night
Jul 20
54°F
Partly Cloudy
3 to 7 mph SW

Partly cloudy, with a low around 54.

Tuesday
Jul 21
78°F
Mostly Sunny
7 to 15 mph S

Mostly sunny, with a high near 78.

Tuesday Night
Jul 21
58°F
Rain Showers Likely
14 mph S

Rain showers likely before 2am, then showers and thunderstorms likely. Mostly cloudy, with a low around 58. Chance of precipitation is 70%.

Wednesday
Jul 22
75°F
Showers And Thunderstorms
12 mph S

Showers and thunderstorms. Mostly cloudy, with a high near 75. Chance of precipitation is 90%.

Wednesday Night
Jul 22
59°F
Showers And Thunderstorms
9 mph S

Showers and thunderstorms. Mostly cloudy, with a low around 59. Chance of precipitation is 80%.

Thursday
Jul 23
74°F
Chance Rain Showers
7 to 10 mph SW

A chance of rain showers. Partly sunny, with a high near 74. Chance of precipitation is 40%.

Thursday Night
Jul 23
56°F
Chance Rain Showers then Partly Cloudy
3 to 7 mph SW

A chance of rain showers before 9pm. Partly cloudy, with a low around 56.

Detailed Forecast

Period Conditions Temp Wind
Saturday
Jul 18
Mostly Cloudy then Widespread Showers And Thunderstorms
71°F
5 to 9 mph
S
Saturday Night
Jul 18
Showers And Thunderstorms
55°F
10 mph
S
Sunday
Jul 19
Rain Showers Likely
68°F
12 to 16 mph
W
Sunday Night
Jul 19
Slight Chance Showers And Thunderstorms then Partly Cloudy
52°F
10 to 14 mph
W
Monday
Jul 20
Sunny
73°F
7 to 10 mph
W
Monday Night
Jul 20
Partly Cloudy
54°F
3 to 7 mph
SW
Tuesday
Jul 21
Mostly Sunny
78°F
7 to 15 mph
S
Tuesday Night
Jul 21
Rain Showers Likely
58°F
14 mph
S
Wednesday
Jul 22
Showers And Thunderstorms
75°F
12 mph
S
Wednesday Night
Jul 22
Showers And Thunderstorms
59°F
9 mph
S
Thursday
Jul 23
Chance Rain Showers
74°F
7 to 10 mph
SW
Thursday Night
Jul 23
Chance Rain Showers then Partly Cloudy
56°F
3 to 7 mph
SW
Weather data provided by the National Weather Service (NOAA). Forecast pages update automatically as new periods are synced for each supported U.S. location.