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

TIDE TIMES for Thursday, August 20, 2026
The tide is currently rising in Grassy Key, north side, Florida Bay, FL.
Next low tide (tomorrow) : 4:20 am (0.9 ft)
Next high tide : in 4h 51m at 11:25 pm (0.7 ft)
Sunset today : 7:53 pm
Sunrise tomorrow : 7:00 am
Moon phase : First Quarter (55% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - Jan 1933

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun6:321.27:220.912:580.31:580.07:085:46Waxing Crescent1Sun
2Mon7:251.08:031.02:100.32:410.27:085:47First Quarter2Mon
3Tue8:250.88:471.03:230.33:230.37:095:47First Quarter3Tue
4Wed9:420.79:361.04:360.24:070.47:095:48First Quarter4Wed
5Thu11:170.610:291.05:460.14:540.57:095:49First Quarter5Thu
6Fri12:420.56:510.05:440.57:095:49Waxing Gibbous6Fri
7Sat1:420.57:48-0.16:340.57:095:50Waxing Gibbous7Sat
8Sun12:111.12:250.58:36-0.27:220.57:095:51Waxing Gibbous8Sun
9Mon12:581.13:000.59:17-0.38:060.47:105:51Waxing Gibbous9Mon
10Tue1:421.23:300.69:54-0.48:470.47:105:52Full Moon10Tue
11Wed2:251.24:010.610:28-0.49:260.37:105:53Full Moon11Wed
12Thu3:071.24:320.711:00-0.410:060.37:105:54Full Moon12Thu
13Fri3:481.35:030.711:32-0.410:470.27:105:54Full Moon13Fri
14Sat4:291.35:350.812:04-0.37:105:55Waning Gibbous14Sat
15Sun5:111.26:070.812:37-0.27:105:56Waning Gibbous15Sun
16Mon5:561.16:390.912:220.11:11-0.17:105:57Waning Gibbous16Mon
17Tue6:450.97:151.01:200.11:470.07:105:57Third Quarter17Tue
18Wed7:440.87:561.02:260.02:250.27:105:58Third Quarter18Wed
19Thu9:030.68:471.03:40-0.13:080.37:095:59Third Quarter19Thu
20Fri10:470.59:501.14:57-0.24:000.37:096:00Third Quarter20Fri
21Sat12:260.46:14-0.45:030.47:096:00Waning Crescent21Sat
22Sun1:360.47:26-0.56:120.37:096:01Waning Crescent22Sun
23Mon12:121.22:270.58:28-0.67:190.37:096:02Waning Crescent23Mon
24Tue1:161.33:080.59:21-0.78:210.17:086:03New Moon24Tue
25Wed2:141.43:450.610:06-0.79:180.07:086:03New Moon25Wed
26Thu3:071.44:190.710:46-0.610:110.07:086:04New Moon26Thu
27Fri3:561.34:520.811:24-0.511:02-0.17:086:05New Moon27Fri
28Sat4:421.35:240.812:00-0.37:076:06Waxing Crescent28Sat
29Sun5:261.15:550.912:35-0.27:076:06Waxing Crescent29Sun
30Mon6:091.06:270.912:46-0.11:090.07:066:07Waxing Crescent30Mon
31Tue6:520.87:001.01:42-0.11:430.17:066:08First Quarter31Tue
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 1:52 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 neap phase. Tonight's moon is 55% 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 (55% 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