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

TIDE TIMES for Friday, September 18, 2026
The tide is currently falling in Grassy Key, north side, Florida Bay, FL.

Next low tide : in 3m at 5:03 pm (0.6 ft)
Next high tide : 10:41 pm (0.8 ft)
Sunset today : 7:24 pm
Sunrise tomorrow : 7:11 am
Moon phase : First Quarter (48% illuminated)
Tide Station Location : Station #8723921
Common Questions About Tides

Grassy Key, north side, Florida Bay, FL Tides - Dec 1871

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Date		High Tide				Low Tide				Sun		Moon	Date
Date		AM	ft	PM	ft	AM	ft	PM	ft	Rise	Set	Moon	Date
1	Fri	5:04	1.4	6:43	0.9			1:07	0.1	6:55	5:38		1	Fri
2	Sat	5:44	1.3	7:30	0.9	12:04	0.8	1:54	0.2	6:56	5:38		2	Sat
3	Sun	6:30	1.3	8:23	0.9	12:48	0.9	2:45	0.3	6:56	5:38		3	Sun
4	Mon	7:24	1.2	9:18	0.9	1:52	0.9	3:38	0.4	6:57	5:38		4	Mon
5	Tue	8:32	1.1	10:09	1.0	3:18	0.9	4:30	0.4	6:58	5:38		5	Tue
6	Wed	9:54	1.1	10:55	1.1	4:41	0.8	5:19	0.5	6:58	5:38		6	Wed
7	Thu	11:14	1.1	11:37	1.2	5:52	0.6	6:05	0.5	6:59	5:39		7	Thu
8	Fri			12:25	1.0	6:53	0.3	6:49	0.6	7:00	5:39		8	Fri
9	Sat	12:18	1.3	1:27	1.0	7:48	0.0	7:32	0.5	7:00	5:39		9	Sat
10	Sun	12:59	1.5	2:24	1.0	8:39	-0.2	8:14	0.5	7:01	5:39		10	Sun
11	Mon	1:43	1.6	3:17	1.0	9:29	-0.4	8:57	0.5	7:02	5:40		11	Mon
12	Tue	2:29	1.6	4:08	0.9	10:18	-0.5	9:40	0.4	7:02	5:40		12	Tue
13	Wed	3:18	1.7	4:57	0.9	11:08	-0.6	10:26	0.4	7:03	5:40		13	Wed
14	Thu	4:08	1.7	5:45	0.8	11:59	-0.5	11:14	0.4	7:04	5:41		14	Thu
15	Fri	5:02	1.6	6:35	0.8			12:52	-0.4	7:04	5:41		15	Fri
16	Sat	5:57	1.5	7:26	0.8	12:09	0.4	1:47	-0.2	7:05	5:41		16	Sat
17	Sun	6:57	1.3	8:21	0.9	1:15	0.5	2:44	0.0	7:05	5:42		17	Sun
18	Mon	8:04	1.2	9:20	0.9	2:32	0.5	3:40	0.2	7:06	5:42		18	Mon
19	Tue	9:22	1.0	10:17	1.0	3:57	0.5	4:34	0.3	7:07	5:43		19	Tue
20	Wed	10:47	0.9	11:09	1.1	5:17	0.4	5:25	0.4	7:07	5:43		20	Wed
21	Thu			12:05	0.9	6:29	0.3	6:13	0.5	7:08	5:44		21	Thu
22	Fri			1:08	0.8	7:29	0.1	6:58	0.5	7:08	5:44		22	Fri
23	Sat	12:35	1.2	2:00	0.8	8:20	0.0	7:40	0.5	7:09	5:45		23	Sat
24	Sun	1:13	1.2	2:44	0.8	9:03	-0.1	8:20	0.5	7:09	5:45		24	Sun
25	Mon	1:48	1.3	3:21	0.7	9:42	-0.2	8:57	0.4	7:09	5:46		25	Mon
26	Tue	2:23	1.3	3:56	0.7	10:18	-0.3	9:33	0.4	7:10	5:46		26	Tue
27	Wed	2:59	1.3	4:29	0.7	10:53	-0.3	10:06	0.4	7:10	5:47		27	Wed
28	Thu	3:36	1.3	5:03	0.7	11:29	-0.3	10:40	0.4	7:11	5:47		28	Thu
29	Fri	4:13	1.3	5:38	0.7			12:04	-0.3	7:11	5:48		29	Fri
30	Sat	4:51	1.2	6:15	0.8			12:41	-0.2	7:11	5:49		30	Sat
31	Sun	5:30	1.2	6:53	0.8			1:20	-0.1	7:12	5:49		31	Sun
Date		High Tide				Low Tide				Sun		Moon	Date
Date		AM	ft	PM	ft	AM	ft	PM	ft	Rise	Set	Moon	Date

Tidal Data Source: (8723921)

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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 neap phase. Tonight's moon is 48% 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 (48% 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

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