Castle Island Sea Conditions and Tide Table

Castle Island Sea Conditions table showing wave height, swell direction and period.

High and low tide times are also provided on the table along with the moon phase and forecast weather. Sunrise today is at 08:17 AM and sunset is at 04:01 PM.

Days 1–3 Weather Summary

A light covering of new snow, mostly falling on Thu night. Becoming milder with moderate rain (total 15mm) heaviest on Sat morning. Icy conditions (max 8°C on Sat morning, min -15°C on Thu night). Winds increasing (light winds from the SSW on Thu night, gales from the SW by Sat afternoon).

Days 4–6 Weather Summary

A light covering of new snow, mostly falling on Sun night. Air temperatures will be below freezing (max 0°C on Sun night, min -11°C on Sun morning). Winds decreasing (gales from the NNW on Mon night, light winds from the SSW by Tue night).

Days 7–9 Weather Summary

A moderate fall of snow, heaviest on Wed night. Temperatures will be below freezing (max 0°C on Wed night, min -14°C on Fri night). Winds decreasing (near gales from the NE on Wed night, calm by Fri night).

Days 10–12 Weather Summary

A dusting of new snow. Temperatures will be below freezing (max -4°C on Tue morning, min -12°C on Sun night). Winds increasing (calm on Sat morning, strong winds from the N by Tue morning).

Thursday
18
Friday
19
Saturday
20
Sunday
21
Monday
22
Tuesday
23
Wednesday
24
Thursday
25
Friday
26
Saturday
27
Sunday
28
Monday
29
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
AM
PM
night
Wave Height Map
High Tide
6:39AM1.10m
6:44PM0.77m
7:10AM1.14m
7:22PM0.77m
7:41AM1.17m
8:00PM0.77m
8:11AM1.19m
8:39PM0.77m
8:42AM1.21m
9:20PM0.78m
9:16AM1.21m
10:04PM0.79m
9:52AM1.19m
10:52PM0.81m
10:34AM1.14m
11:43PM0.83m
11:21AM1.08m
00:40AM0.86m
12:17PM1.00m
1:46AM0.90m
1:23PM0.93m
2:58AM0.95m
2:42PM0.87m
4:06AM1.02m
Low Tide
1:08PM0.28m
00:20AM0.23m
1:43PM0.25m
00:57AM0.20m
2:18PM0.23m
1:33AM0.18m
2:53PM0.22m
2:08AM0.19m
3:27PM0.22m
2:43AM0.23m
4:01PM0.24m
3:19AM0.28m
4:35PM0.27m
3:57AM0.35m
5:10PM0.30m
4:40AM0.44m
5:48PM0.35m
5:32AM0.52m
6:33PM0.38m
6:53AM0.58m
7:36PM0.41m
9:41AM0.54m
9:03PM0.40m
Wave
height (m) 
direction
period (s) 
1.3
NE
9
1.4
NE
11
0.8
NE
13
1
NE
11
1.6
SW
6
2.5
SSE
7
3
SSE
10
3
SW
8
2.4
SW
7
1.1
SW
6
0.6
ESE
10
0.9
SE
4
1.3
SE
8
1.2
SE
9
1.9
ESE
9
1.8
NE
10
1.3
NE
10
0.9
NNE
11
0.7
NE
11
1.3
SE
5
2.3
ESE
8
2.1
ESE
11
2
ESE
11
1.9
ESE
11
1.3
ESE
10
1.2
E
10
0.8
E
10
0.8
E
9
0.9
E
9
0.9
NE
11
1.8
E
11
1.7
E
11
1
E
11
0.9
ENE
11
1
E
10
1.3
E
9
clear
clear
light snow
light snow
cloud
mod rain
mod rain
part cloud
part cloud
part cloud
cloud
light snow
light snow
cloud
light snow
part cloud
part cloud
part cloud
light snow
light snow
heavy snow
snow showers
snow showers
part cloud
part cloud
clear
part cloud
cloud
light snow
cloud
part cloud
clear
part cloud
clear
part cloud
cloud
clear
clear
light snow
light snow
cloudy
mod rain
mod rain
some clouds
some clouds
some clouds
cloudy
light snow
light snow
cloudy
light snow
some clouds
some clouds
some clouds
light snow
light snow
heavy snow
snow shwrs
snow shwrs
some clouds
some clouds
clear
some clouds
cloudy
light snow
cloudy
some clouds
clear
some clouds
clear
some clouds
cloudy
 km/h
45
NW
45
W
15
W
25
SSW
40
SW
60
S
65
SW
70
SW
65
WSW
35
WSW
15
SSW
30
ESE
25
ENE
20
NNW
65
NNW
45
NW
35
WNW
20
WSW
25
SE
35
ESE
60
NE
15
ESE
45
NW
50
WNW
30
W
25
W
10
WNW
10
NNE
25
N
30
WNW
35
WSW
30
WSW
15
W
15
NNW
30
N
40
N
 mm 
6
9
max°C
-9
-10
-12
-2
3
6
8
1
-9
-9
-7
0
0
0
0
-1
-4
-8
-3
-1
0
0
-1
-5
-9
-9
-12
-10
-9
-9
-10
-10
-11
-10
-8
-5
Moonrise
7:31
8:34
9:26
10:04
10:32
10:52
11:08
11:20
11:32
11:43
11:55
12:09
Moonset
2:18
3:01
3:58
5:06
6:22
7:40
8:59
10:18
11:38
12:59
2:24
Sunrise
8:17
8:17
8:18
8:18
8:18
8:18
8:19
8:19
8:19
8:21
8:21
8:21
Sunset
4:01
4:02
4:02
4:04
4:04
4:05
4:05
4:06
4:07
4:07
4:07
4:08
Today's sea temperature in Castle Island is
0.9° C
(Statistics for 18 Dec 1981-2005 – mean: 0.0 max: 0.7 min: -0.6°C)
Issued (local time): 1 am Thursday 18 Dec 2025
Forecast update inUpdates in  hr  min  sUpdate imminent
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