Tides Today & Tomorrow in Southwest Harbor, ME

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Southwest Harbor, ME.
Next low tide : 9:43 pm (0.8 ft)
Next high tide : in 3h 46m at 3:46 pm (10.5 ft)
Sunset today : 7:33 pm
Sunrise tomorrow : 5:40 am
Moon phase : First Quarter (36% illuminated)
Tide Station Location : Station #8413564
Common Questions About Tides

Southwest Harbor, ME Tides - Dec 1960

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu9:1111.49:4210.52:340.23:07-0.56:493:55Full Moon1Thu
2Fri9:5411.410:2610.43:190.33:51-0.56:503:55Full Moon2Fri
3Sat10:3511.311:0610.34:010.44:32-0.46:513:55Full Moon3Sat
4Sun11:1311.211:4510.14:410.75:11-0.26:523:54Full Moon4Sun
5Mon11:5111.05:200.95:490.06:533:54Waning Gibbous5Mon
6Tue12:249.912:2910.75:581.16:280.26:543:54Waning Gibbous6Tue
7Wed1:039.71:0910.46:371.47:070.56:553:54Waning Gibbous7Wed
8Thu1:439.61:5010.17:191.57:480.76:563:54Waning Gibbous8Thu
9Fri2:269.42:359.88:031.78:310.96:573:54Third Quarter9Fri
10Sat3:119.43:239.68:511.89:171.06:583:54Third Quarter10Sat
11Sun4:009.44:159.49:421.710:071.16:593:54Third Quarter11Sun
12Mon4:509.55:119.310:371.510:581.06:593:54Third Quarter12Mon
13Tue5:439.96:079.511:331.111:510.97:003:54Waning Crescent13Tue
14Wed6:3510.37:039.812:290.67:013:54Waning Crescent14Wed
15Thu7:2610.97:5810.212:440.61:220.07:023:55Waning Crescent15Thu
16Fri8:1611.68:5010.71:350.22:14-0.77:023:55Waning Crescent16Fri
17Sat9:0612.29:4111.12:26-0.23:04-1.37:033:55New Moon17Sat
18Sun9:5612.610:3211.43:17-0.53:55-1.77:043:55New Moon18Sun
19Mon10:4612.911:2311.64:08-0.74:46-1.97:043:56New Moon19Mon
20Tue11:3812.95:01-0.75:38-1.97:053:56Waxing Crescent20Tue
21Wed12:1611.612:3212.75:55-0.76:32-1.77:053:57Waxing Crescent21Wed
22Thu1:1111.51:2812.26:52-0.57:27-1.37:063:57Waxing Crescent22Thu
23Fri2:0811.32:2711.67:52-0.28:25-0.97:063:58First Quarter23Fri
24Sat3:0711.03:3011.08:540.19:25-0.47:073:58First Quarter24Sat
25Sun4:0910.84:3510.59:590.310:270.07:073:59First Quarter25Sun
26Mon5:1110.75:4110.111:050.411:280.47:074:00First Quarter26Mon
27Tue6:1210.76:459.912:080.37:084:00Waxing Gibbous27Tue
28Wed7:1010.77:439.812:270.51:070.17:084:01Waxing Gibbous28Wed
29Thu8:0310.88:369.91:220.62:000.07:084:02Waxing Gibbous29Thu
30Fri8:5110.99:249.92:130.62:48-0.27:084:03Waxing Gibbous30Fri
31Sat9:3411.02:590.73:32-0.37:084:04Full Moon31Sat
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8413564)

Common Questions About Southwest Harbor, ME Tides

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What time does the tide turn (slack tide) in Southwest Harbor, ME today?

Slack tide in Southwest Harbor, ME is approximately 6:44 pm — midway between the next high and low tide, when tidal current is weakest. This is the preferred window for boat crossings, underwater visibility, and fishing in areas with strong currents.

Is this week a spring tide or neap tide in Southwest Harbor, ME?

Southwest Harbor, ME is currently in a transitional phase. Tonight's moon is 36% illuminated. Spring tides (largest swings) occur near new and full moons; neap tides (smallest swings) occur near first and third quarter moons. Tidal ranges this week are shifting between spring and neap.

What datum are Southwest Harbor, ME tide heights measured from?

Tide heights on this page are measured from Mean Lower Low Water (MLLW), the U.S. NOAA standard. A height of 0 ft represents the 19-year average of each day's lower low tide. Negative values indicate a "minus tide" — water levels below that long-term reference.

What factors can affect the tide predictions for Southwest Harbor, ME?

Tide predictions for Southwest Harbor, ME come from NOAA's harmonic analysis and are typically accurate within about ±10 minutes on timing and ±0.5 ft on height. Actual water levels can deviate further due to sustained winds, atmospheric pressure changes, river flow, and storm surge. During major weather events, be sure to check US Harbors weather pages for factors that could impact tidal predictions.

Which NOAA station provides tide data for Southwest Harbor, ME?

Tide data for Southwest Harbor, ME is sourced from NOAA Station #8413564. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8413564.

What is the moon phase in Southwest Harbor, ME tonight?

Tonight the moon over Southwest Harbor, ME is First Quarter (36% illuminated). This places Southwest Harbor, ME in a transitional tide cycle, so tidal ranges are shifting between spring and neap this week.

US Harbors Tidal Data

The data in our tide charts, tide tables, and tide graphs is provided by NOAA and others. These predictions are derived mathematically from numerous inputs, including data from historical tide stations and nearby locations where sensors are actively recording. As shown in the tide graph at the top of this page, “Predicted” tides (blue) are what forecasting models expect to happen. “Observed” tides (red) are those recorded by local sensors in real time, overlaid on the predictions for direct comparison. We display Observed water levels for a select group of harbors including Portland, Maine, where a physical sensor monitors water levels in real time.

LEARN MORE ABOUT OUR TIDE DATA