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 1h 38m 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 - Oct 1932

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat3:221.74:211.510:370.110:380.86:156:11New Moon1Sat
2Sun3:591.85:121.411:270.111:120.96:166:10Waxing Crescent2Sun
3Mon4:391.86:051.212:210.16:166:08Waxing Crescent3Mon
4Tue5:241.87:041.11:210.16:166:07Waxing Crescent4Tue
5Wed6:151.88:161.012:261.02:300.36:176:06First Quarter5Wed
6Thu7:171.79:510.91:131.13:470.46:176:05First Quarter6Thu
7Fri8:351.611:191.02:231.15:080.56:186:04First Quarter7Fri
8Sat10:051.64:011.26:190.66:186:03Waxing Gibbous8Sat
9Sun12:131.111:28 AM1.65:331.17:130.76:196:02Waxing Gibbous9Sun
10Mon12:521.212:341.66:481.07:530.86:196:02Waxing Gibbous10Mon
11Tue1:231.31:271.67:480.98:270.86:196:01Waxing Gibbous11Tue
12Wed1:511.42:121.68:370.78:570.96:206:00Full Moon12Wed
13Thu2:171.52:521.59:200.69:250.96:205:59Full Moon13Thu
14Fri2:411.63:291.49:580.59:530.96:215:58Full Moon14Fri
15Sat3:071.64:051.410:350.410:190.96:215:57Full Moon15Sat
16Sun3:331.74:401.311:110.410:451.06:225:56Waning Gibbous16Sun
17Mon4:021.65:171.211:480.411:081.06:225:55Waning Gibbous17Mon
18Tue4:331.65:581.112:280.46:235:54Waning Gibbous18Tue
19Wed5:081.66:451.01:130.56:235:53Waning Gibbous19Wed
20Thu5:461.67:441.02:080.56:245:52Waning Gibbous20Thu
21Fri6:331.59:001.012:221.23:140.66:245:52Third Quarter21Fri
22Sat7:331.510:221.01:081.34:240.76:255:51Third Quarter22Sat
23Sun8:531.511:161.12:461.35:260.76:255:50Third Quarter23Sun
24Mon10:191.511:531.24:381.36:170.76:265:49Waning Crescent24Mon
25Tue11:341.55:591.17:000.86:265:48Waning Crescent25Tue
26Wed12:251.312:381.57:020.87:380.86:275:48Waning Crescent26Wed
27Thu12:571.51:361.57:570.58:140.86:285:47Waning Crescent27Thu
28Fri1:311.62:301.58:480.38:490.86:285:46New Moon28Fri
29Sat2:061.83:231.49:380.09:250.86:295:45New Moon29Sat
30Sun2:451.94:151.310:27-0.110:010.86:295:45New Moon30Sun
31Mon3:281.95:071.211:18-0.210:390.96:305:44Waxing Crescent31Mon
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