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

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently rising in Grassy Key, north side, Florida Bay, FL.
Next low tide : 5:15 pm (0.3 ft)
Next high tide : in 4h 01m at 9:23 am (1.2 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 - Mar 2079

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed1:301.12:510.69:22-0.38:410.26:456:26Waning Crescent1Wed
2Thu2:171.23:170.79:53-0.39:250.16:446:26New Moon2Thu
3Fri3:021.23:440.910:22-0.310:08-0.16:436:27New Moon3Fri
4Sat3:471.24:131.010:52-0.210:52-0.26:426:27New Moon4Sat
5Sun4:321.24:431.111:22-0.111:39-0.46:426:28Waxing Crescent5Sun
6Mon5:181.15:141.111:530.06:416:28Waxing Crescent6Mon
7Tue6:080.95:491.212:30-0.412:250.16:406:29Waxing Crescent7Tue
8Wed7:020.76:281.21:27-0.512:590.26:396:29Waxing Crescent8Wed
9Thu8:100.57:171.12:31-0.41:370.36:386:30First Quarter9Thu
10Fri9:450.48:231.13:46-0.42:260.46:376:30First Quarter10Fri
11Sat11:370.49:531.15:08-0.33:410.56:366:30First Quarter11Sat
12Sun1:480.57:30-0.36:160.57:357:31Waxing Gibbous12Sun
13Mon12:251.12:320.68:39-0.37:400.47:347:31Waxing Gibbous13Mon
14Tue1:391.23:070.79:30-0.38:490.27:337:32Waxing Gibbous14Tue
15Wed2:391.23:380.810:10-0.29:460.17:327:32Waxing Gibbous15Wed
16Thu3:301.24:070.910:43-0.210:35-0.17:317:33Full Moon16Thu
17Fri4:151.24:351.011:14-0.111:20-0.27:307:33Full Moon17Fri
18Sat4:571.15:011.111:440.07:297:34Full Moon18Sat
19Sun5:351.15:281.112:02-0.212:130.17:287:34Waning Gibbous19Sun
20Mon6:121.05:551.212:43-0.312:410.27:277:35Waning Gibbous20Mon
21Tue6:490.86:231.11:24-0.31:080.37:267:35Waning Gibbous21Tue
22Wed7:270.76:551.12:08-0.21:320.47:257:35Waning Gibbous22Wed
23Thu8:120.67:301.02:56-0.21:520.47:247:36Third Quarter23Thu
24Fri9:110.58:141.03:53-0.12:070.57:237:36Third Quarter24Fri
25Sat10:550.49:130.95:010.02:160.67:217:37Third Quarter25Sat
26Sun10:350.96:160.07:207:37Third Quarter26Sun
27Mon1:530.57:250.06:200.77:197:38Third Quarter27Mon
28Tue12:001.02:130.68:200.07:380.67:187:38Waning Crescent28Tue
29Wed1:101.12:360.79:020.08:360.47:177:38Waning Crescent29Wed
30Thu2:071.13:010.99:370.09:250.27:167:39Waning Crescent30Thu
31Fri2:591.23:281.010:080.010:110.07:157:39New Moon31Fri
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 1:19 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