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

TIDE TIMES for Friday, July 31, 2026
The tide is currently falling in Grassy Key, north side, Florida Bay, FL.
Next low tide (tomorrow) : in 4h 45m at 12:47 am (0.1 ft)
Next high tide (tomorrow) : 6:16 am (1.0 ft)
Sunset today : 8:08 pm
Sunrise tomorrow : 6:51 am
Moon phase : Waning Gibbous (96% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - Sep 1966

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu5:141.25:091.511:420.67:047:42Full Moon1Thu
2Fri5:391.35:451.412:220.512:200.67:057:41Waning Gibbous2Fri
3Sat6:061.36:231.412:480.612:580.67:057:40Waning Gibbous3Sat
4Sun6:341.47:031.21:130.71:400.57:057:39Waning Gibbous4Sun
5Mon7:031.47:471.11:370.82:270.57:067:38Waning Gibbous5Mon
6Tue7:361.48:421.02:020.83:240.57:067:37Third Quarter6Tue
7Wed8:151.49:580.92:310.94:310.57:067:36Third Quarter7Wed
8Thu9:071.411:440.83:081.05:470.47:077:35Third Quarter8Thu
9Fri10:181.54:051.17:020.47:077:34Third Quarter9Fri
10Sat1:110.911:40 AM1.55:301.18:080.37:077:33Waning Crescent10Sat
11Sun2:040.912:551.66:551.09:020.37:087:32Waning Crescent11Sun
12Mon2:441.02:001.78:070.99:480.27:087:31Waning Crescent12Mon
13Tue3:191.12:591.89:090.710:290.37:087:30New Moon13Tue
14Wed3:541.33:531.810:060.511:070.47:097:29New Moon14Wed
15Thu4:281.44:461.811:000.411:430.57:097:28New Moon15Thu
16Fri5:041.55:381.711:530.27:107:27Waxing Crescent16Fri
17Sat5:401.66:291.512:190.612:470.27:107:26Waxing Crescent17Sat
18Sun6:191.77:221.312:560.71:430.27:107:25Waxing Crescent18Sun
19Mon7:001.78:191.11:330.82:440.37:117:24Waxing Crescent19Mon
20Tue7:461.79:301.02:120.93:520.47:117:22First Quarter20Tue
21Wed8:411.611:100.92:581.05:070.57:117:21First Quarter21Wed
22Thu9:501.53:591.16:250.57:127:20First Quarter22Thu
23Fri12:510.911:13 AM1.55:201.27:370.67:127:19Waxing Gibbous23Fri
24Sat1:491.012:301.56:411.18:350.67:127:18Waxing Gibbous24Sat
25Sun2:261.11:311.57:501.19:170.67:137:17Waxing Gibbous25Sun
26Mon2:541.22:201.68:471.09:510.67:137:16Waxing Gibbous26Mon
27Tue3:181.23:021.69:330.910:200.77:147:15Full Moon27Tue
28Wed3:391.33:401.610:140.810:470.77:147:14Full Moon28Wed
29Thu4:021.44:161.610:510.711:130.87:147:13Full Moon29Thu
30Fri4:261.54:521.511:260.611:370.87:157:12Full Moon30Fri
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8723921)

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

Show All
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 3:31 am — 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 96% 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 Waning Gibbous (96% 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