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

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently falling in Grassy Key, north side, Florida Bay, FL.
Next low tide : in 3h 41m at 5:15 pm (0.3 ft)
Next high tide : 10:22 pm (0.7 ft)
Sunset today : 8:13 pm
Sunrise tomorrow : 6:46 am
Moon phase : First Quarter (52% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - May 2079

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon4:271.03:481.510:270.311:31-0.66:477:53New Moon1Mon
2Tue5:191.04:281.511:030.46:477:54New Moon2Tue
3Wed6:110.85:131.512:21-0.711:40 AM0.46:467:54Waxing Crescent3Wed
4Thu7:050.76:011.51:14-0.712:200.46:457:55Waxing Crescent4Thu
5Fri8:030.76:551.42:11-0.61:050.56:457:55Waxing Crescent5Fri
6Sat9:080.67:581.33:15-0.42:030.66:447:56First Quarter6Sat
7Sun10:210.69:121.24:23-0.23:240.66:437:56First Quarter7Sun
8Mon11:300.710:401.15:300.05:010.66:437:57First Quarter8Mon
9Tue12:240.86:300.16:300.56:427:57First Quarter9Tue
10Wed12:071.11:061.07:210.27:440.46:427:58Waxing Gibbous10Wed
11Thu1:191.01:411.18:040.38:440.26:417:58Waxing Gibbous11Thu
12Fri2:181.02:121.28:410.49:330.06:417:59Waxing Gibbous12Fri
13Sat3:090.92:421.39:160.410:15-0.16:407:59Waxing Gibbous13Sat
14Sun3:530.93:101.39:490.510:54-0.26:408:00Full Moon14Sun
15Mon4:330.83:401.310:200.511:30-0.36:398:00Full Moon15Mon
16Tue5:100.84:111.310:500.56:398:01Full Moon16Tue
17Wed5:480.74:441.312:07-0.311:18 AM0.56:388:01Full Moon17Wed
18Thu6:260.75:191.312:44-0.311:45 AM0.56:388:02Waning Gibbous18Thu
19Fri7:070.75:561.31:24-0.312:130.66:378:02Waning Gibbous19Fri
20Sat7:520.66:371.22:07-0.212:440.66:378:03Waning Gibbous20Sat
21Sun8:420.77:231.22:55-0.11:250.76:378:03Waning Gibbous21Sun
22Mon9:370.78:171.13:470.02:290.86:368:04Third Quarter22Mon
23Tue10:310.79:241.14:400.14:020.86:368:04Third Quarter23Tue
24Wed11:180.810:431.05:300.25:330.76:368:05Third Quarter24Wed
25Thu11:591.06:170.36:470.56:358:05Third Quarter25Thu
26Fri12:051.012:361.17:010.37:500.26:358:06Waning Crescent26Fri
27Sat1:180.91:131.27:430.48:46-0.16:358:06Waning Crescent27Sat
28Sun2:240.91:521.48:240.49:39-0.46:358:07Waning Crescent28Sun
29Mon3:240.92:341.59:060.410:31-0.66:348:07New Moon29Mon
30Tue4:210.83:191.69:470.411:22-0.76:348:08New Moon30Tue
31Wed5:150.84:081.610:300.46:348:08New Moon31Wed
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 7:48 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 neap phase. Tonight's moon is 52% 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 minimum.

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 First Quarter (52% illuminated). This places Grassy Key, north side, Florida Bay, FL in a neap tide cycle, so tidal ranges are near their weekly minimum 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