Tides Today & Tomorrow in Grassy Key, north side, Florida Bay, FL

TIDE TIMES for Sunday, August 16, 2026
The tide is currently rising in Grassy Key, north side, Florida Bay, FL.
Next low tide (tomorrow) : 1:46 am (0.5 ft)
Next high tide : in 27m at 7:00 pm (1.3 ft)
Sunset today : 7:57 pm
Sunrise tomorrow : 6:58 am
Moon phase : Waxing Crescent (18% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - Sep 1939

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri5:311.35:481.412:090.512:210.57:047:43Waning Gibbous1Fri
2Sat6:011.46:261.312:360.51:000.57:047:42Waning Gibbous2Sat
3Sun6:341.47:081.21:040.61:420.57:057:41Waning Gibbous3Sun
4Mon7:091.47:541.11:330.72:320.57:057:40Waning Gibbous4Mon
5Tue7:481.48:511.02:060.83:310.57:057:39Third Quarter5Tue
6Wed8:371.410:060.92:470.84:400.57:067:38Third Quarter6Wed
7Thu9:391.411:340.93:430.95:530.57:067:37Third Quarter7Thu
8Fri10:561.54:561.07:010.47:067:36Waning Crescent8Fri
9Sat12:471.012:121.56:150.98:020.47:077:35Waning Crescent9Sat
10Sun1:411.11:201.67:270.88:530.47:077:34Waning Crescent10Sun
11Mon2:261.22:211.78:320.79:390.37:087:33Waning Crescent11Mon
12Tue3:071.33:171.79:300.510:210.47:087:31New Moon12Tue
13Wed3:471.44:091.710:240.311:010.47:087:30New Moon13Wed
14Thu4:261.65:001.611:160.211:400.57:097:29New Moon14Thu
15Fri5:071.65:501.512:080.17:097:28Waxing Crescent15Fri
16Sat5:481.76:391.412:200.61:000.27:097:27Waxing Crescent16Sat
17Sun6:311.77:291.31:000.71:550.27:107:26Waxing Crescent17Sun
18Mon7:161.68:241.11:420.82:550.47:107:25First Quarter18Mon
19Tue8:071.69:291.02:300.94:010.57:107:24First Quarter19Tue
20Wed9:051.510:541.03:271.05:110.67:117:23First Quarter20Wed
21Thu10:161.44:361.06:210.77:117:22First Quarter21Thu
22Fri12:191.011:33 AM1.45:521.17:240.77:127:21Waxing Gibbous22Fri
23Sat1:171.112:411.47:031.08:160.77:127:20Waxing Gibbous23Sat
24Sun1:571.212:361.57:031.07:580.76:126:19Waxing Gibbous24Sun
25Mon1:281.21:211.57:530.98:340.76:136:18Waxing Gibbous25Mon
26Tue1:551.32:021.58:370.89:050.76:136:17Full Moon26Tue
27Wed2:211.42:401.59:150.79:340.76:136:15Full Moon27Wed
28Thu2:491.53:171.59:510.610:010.86:146:14Full Moon28Thu
29Fri3:191.53:551.510:260.510:280.86:146:13Full Moon29Fri
30Sat3:491.64:331.411:010.410:550.86:156:12Waning Gibbous30Sat
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8723921)

Common Questions About Grassy Key, north side, Florida Bay, FL Tides

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What time does the tide turn (slack tide) in Grassy Key, north side, Florida Bay, FL today?

Slack tide in Grassy Key, north side, Florida Bay, FL is approximately 10:23 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 Grassy Key, north side, Florida Bay, FL?

Grassy Key, north side, Florida Bay, FL is currently in a spring phase. Tonight's moon is 18% 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 near their weekly maximum.

What datum are Grassy Key, north side, Florida Bay, FL 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 Grassy Key, north side, Florida Bay, FL?

Tide predictions for Grassy Key, north side, Florida Bay, FL 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 Grassy Key, north side, Florida Bay, FL?

Tide data for Grassy Key, north side, Florida Bay, FL is sourced from NOAA Station #8723921. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8723921.

What is the moon phase in Grassy Key, north side, Florida Bay, FL tonight?

Tonight the moon over Grassy Key, north side, Florida Bay, FL is Waxing Crescent (18% illuminated). This places Grassy Key, north side, Florida Bay, FL in a spring tide cycle, so tidal ranges are near their weekly maximum 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