Grassy Key, north side, Florida Bay Tides Today
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Grassy Key, north side, Florida Bay runs a mean tidal range of about 0.7 ft. This month the highest water, 1.9 ft, comes on the morning of Oct 29, and the lowest, a -0.1 ft minus tide, on the afternoon of Oct 28.
| Low tide | 1:20 AM | 1.0 ft |
| High tide | 7:19 AM | 1.7 ft |
| Low tide | 3:39 PM | 0.3 ft |
| High tide | 9:26 PM | 1.0 ft |
Today on the water at Grassy Key, north side, Florida Bay
Today at Grassy Key, north side, Florida Bay: high tide at 7:19 AM (1.7 ft) and 9:26 PM (1.0 ft), low tide at 1:20 AM (1.0 ft) and 3:39 PM (0.3 ft). The National Weather Service forecast for today is chance showers and thunderstorms with E winds 10 mph, 82°F. In effect now: Coastal Flood Warning. Sunrise is at 7:29 AM and sunset at 6:45 PM.
| Period | Forecast | Wind | Temp |
|---|---|---|---|
| Today | Chance Showers And Thunderstorms | E 10 mph | 82°F |
| Tonight | Showers And Thunderstorms Likely | E 10 to 15 mph | 77°F |
Forecast: National Weather Service point forecast for this location.
Where Grassy Key, north side, Florida Bay is
Grassy Key, north side, Florida Bay sits at 24.7717° N, 80.9400° W on the Florida Keys, where the Atlantic meets Florida Bay and the Gulf of Mexico, at Marathon, FL, in Mainland Monroe County. The station here is a subordinate tide prediction point. NOAA has no gauge in the water at this spot; its times and heights are published as offsets from a reference gauge, named below. The closest gauge measuring live water level is Vaca Key, USCG Station, Florida Bay (NOAA 8723970), 11.3 mi away, and high and low water here run on average about 170 min later than there. The nearest weather station is Long Key, FL, a shore station reporting wind and, at most sites, water temperature, 6.9 mi away.
The tide at Grassy Key, north side, Florida Bay
Grassy Key, north side, Florida Bay has a mixed tide: two highs and two lows a day, but of unequal size, so one low each day drains a little lower than the other. This month's predictions average 1.9 high tides a day here. The mean range from lower low to higher high is 1.3 ft, and 0.9 ft between the average high and the average low, a small tide. On an average day the higher high tops the lower high by 0.2 ft and the lower low sits 0.2 ft below the other low. For the water around it: The Keys sit on a tidal seam: the ocean side has two semidiurnal highs a day near 2 ft, while the bay side is smaller and more diurnal, so tides on opposite sides of one key can differ by hours.
About this station
- High tide reaches Grassy Key, north side, Florida Bay about 8.4 hours after the moon passes overhead. That lag is local, which is why high water does not line up with the moon.
- Highest water on record: 2.3 ft on Feb 19, 1972.
- Lowest on record: -1.2 ft on Feb 4, 1971.
- NOAA predicts tides here from Key West, station 8724580. High tide comes about 340 min later and low tide about 408 min later than there.
- High tide heights run about 0.73 times the reference.
Datum and source
Heights on this page are feet above mean lower low water (MLLW), the zero NOAA's nautical charts use for soundings. A predicted 0.0 ft low is the average of the lower low each day; a minus tide is water below chart datum, and a 2 ft high means 2 ft more water than the chart shows. NOAA fixes MLLW at Grassy Key, north side, Florida Bay from the 1983-2001 National Tidal Datum Epoch; mean higher high water is 1.3 ft above it and mean sea level 0.6 ft. The land survey datum NAVD88, the zero on topographic maps and flood maps, is 1.4 ft above MLLW here, so a water level on this page converts to NAVD88 by subtracting that amount. These datums are controlled from NOAA's Key West, FL gauge. Source: NOAA CO-OPS station 8723921, established 1970, gauge removed 1982. The tide times and heights are published as time and height offsets from its reference gauge; TidalMap republishes them daily and does not alter them.
Tide stations near Grassy Key, north side, Florida Bay
- Long Key, western end: 6.1 mi, tides about 270 min later
- Long Key Bight, Long Key: 9.1 mi, tides about 274 min later
- Money Key: 18.4 mi, tides about 204 min earlier
- Missouri Key-Little Duck Key Channel: 19.6 mi, tides about 298 min later
- Snake Creek, USCG Station, Plantation Key: 25.5 mi, tides about 61 min earlier
TidalMapMonthly tide calendar
🌊 Biggest flood tides at Grassy Key, north side, Florida Bay this month: Oct 1, Oct 12, Oct 26, Oct 27, Oct 28, Oct 29, Oct 30, Oct 31. These spring highs push water up into the grass and over the oyster rock; prime for poling into flooded marsh for tailing reds.
🔻 Negative (minus) low tides at Grassy Key, north side, Florida Bay this month: Oct 27, Oct 28. These drain the flats and expose the oyster rock, prime for sight-fishing and clamming.
Best fishing times (solunar)
Major and minor solunar windows for Grassy Key, north side, Florida Bay, peak feeding activity is around the moon overhead/underfoot (majors) and moonrise/moonset (minors). Score is the day's activity coefficient (0–100).
| Day | Major windows | Minor windows | Score |
|---|---|---|---|
| Today 🌖 | 5:03–7:03 AM 5:28–7:28 PM | — 12:10–2:10 PM | 55 |
| Sun Nov 1 🌗 | 6:03–8:03 AM 6:28–8:28 PM | 11:01–1:01 AM 12:59–2:59 PM | 42 |
| Mon Nov 2 🌗 | 6:59–8:59 AM 7:24–9:24 PM | 12:09–2:09 AM 1:42–3:42 PM | 33 |
| Tue Nov 3 🌗 | 7:50–9:50 AM 8:15–10:15 PM | 1:14–3:14 AM 2:20–4:20 PM | 47 |
| Wed Nov 4 🌗 | 8:38–10:38 AM 9:03–11:03 PM | 2:15–4:15 AM 2:55–4:55 PM | 60 |
| Thu Nov 5 🌘 | 9:24–11:24 AM 9:49–11:49 PM | 3:14–5:14 AM 3:28–5:28 PM | 73 |
| Fri Nov 6 🌘 | 10:09–12:09 PM 10:34–12:34 AM | 4:12–6:12 AM 4:01–6:01 PM | 83 |
Predictions & observations: NOAA CO-OPS station 8723921. Solunar windows computed from the moon's position for this location. Times shown in the station's local time. Not for navigation.
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