24.7717’ N, 80.9400’ W

Grassy Key, north side, Florida Bay, FL

78°
H 85°
L 80°
ESE
5mph
Low tide
4:41 am

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

TIDE TIMES for Sunday, September 20, 2026
The tide is currently falling in Grassy Key, north side, Florida Bay, FL.
Next low tide : in 47m at 4:41 am (1.2 ft)
Next high tide : 10:41 am (1.4 ft)
Sunset today : 7:22 pm
Sunrise tomorrow : 7:11 am
Moon phase : First Quarter (67% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - Dec 1868

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue3:251.64:511.011:05-0.210:310.66:555:38Full Moon1Tue
2Wed4:091.65:371.011:51-0.211:150.66:565:38Waning Gibbous2Wed
3Thu4:551.66:261.012:40-0.26:575:38Waning Gibbous3Thu
4Fri5:461.57:181.012:040.61:33-0.16:585:38Waning Gibbous4Fri
5Sat6:431.48:141.01:040.62:300.16:585:38Third Quarter5Sat
6Sun7:501.39:141.02:170.73:290.26:595:39Third Quarter6Sun
7Mon9:101.210:151.13:400.64:280.37:005:39Third Quarter7Mon
8Tue10:371.111:101.25:020.55:250.47:005:39Waning Crescent8Tue
9Wed11:561.06:150.36:170.57:015:39Waning Crescent9Wed
10Thu12:011.31:031.07:190.17:070.57:025:40Waning Crescent10Thu
11Fri12:471.41:591.08:150.07:530.57:025:40Waning Crescent11Fri
12Sat1:301.42:481.09:03-0.28:360.57:035:40New Moon12Sat
13Sun2:111.53:320.99:47-0.29:180.47:045:41New Moon13Sun
14Mon2:511.54:120.910:29-0.39:590.47:045:41New Moon14Mon
15Tue3:291.54:500.911:09-0.310:380.47:055:41New Moon15Tue
16Wed4:071.45:260.911:49-0.211:190.57:055:42Waxing Crescent16Wed
17Thu4:461.36:020.912:29-0.17:065:42Waxing Crescent17Thu
18Fri5:241.36:400.912:000.51:110.07:065:42Waxing Crescent18Fri
19Sat6:051.27:200.912:460.61:550.17:075:43Waxing Crescent19Sat
20Sun6:501.18:040.91:400.62:400.27:075:43First Quarter20Sun
21Mon7:421.08:530.92:470.63:270.37:085:44First Quarter21Mon
22Tue8:450.99:450.94:000.64:150.47:085:44First Quarter22Tue
23Wed10:030.810:361.05:100.55:020.47:095:45First Quarter23Wed
24Thu11:220.811:241.16:120.35:490.57:095:46Waxing Gibbous24Thu
25Fri12:300.87:070.16:340.57:105:46Waxing Gibbous25Fri
26Sat12:091.21:280.87:56-0.17:190.47:105:47Waxing Gibbous26Sat
27Sun12:541.22:190.88:41-0.38:020.47:115:47Waxing Gibbous27Sun
28Mon1:381.33:060.89:25-0.48:460.37:115:48Full Moon28Mon
29Tue2:241.43:510.810:08-0.59:310.27:115:48Full Moon29Tue
30Wed3:111.44:350.810:52-0.610:170.27:125:49Full Moon30Wed
31Thu4:001.55:180.811:37-0.611:060.17:125:50Waning Gibbous31Thu
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8723921)

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

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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 transitional phase. Tonight's moon is 67% 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 shifting between spring and neap.

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 (67% illuminated). This places Grassy Key, north side, Florida Bay, FL in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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