Tides Today & Tomorrow in Upper Guadalupe Slough, CA

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently falling in Upper Guadalupe Slough, CA.
Next low tide (tomorrow) : in 5h 49m at 1:27 am (1.3 ft)
Next high tide (tomorrow) : 7:15 am (6.4 ft)
Sunset today : 7:56 pm
Sunrise tomorrow : 6:27 am
Moon phase : First Quarter (37% illuminated)
Tide Station Location : Station #9414549
Common Questions About Tides

Upper Guadalupe Slough, CA Tides - Feb 1929

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri6:029.17:335.912:082.21:591.47:115:32Third Quarter1Fri
2Sat6:479.19:196.21:062.93:041.07:105:33Third Quarter2Sat
3Sun7:359.210:306.72:153.44:010.67:095:34Waning Crescent3Sun
4Mon8:259.311:197.23:243.74:490.27:085:35Waning Crescent4Mon
5Tue9:139.511:567.54:233.85:31-0.17:075:36Waning Crescent5Tue
6Wed9:599.85:103.76:08-0.37:065:37Waning Crescent6Wed
7Thu12:287.710:41 AM10.05:513.56:42-0.57:055:38New Moon7Thu
8Fri12:577.811:22 AM10.16:273.37:14-0.77:045:39New Moon8Fri
9Sat1:247.912:0110.17:023.17:45-0.77:035:40New Moon9Sat
10Sun1:508.112:409.97:372.88:15-0.77:025:41New Moon10Sun
11Mon2:188.31:209.68:162.58:47-0.47:015:43Waxing Crescent11Mon
12Tue2:468.52:049.08:582.29:190.07:005:44Waxing Crescent12Tue
13Wed3:158.82:538.29:461.99:540.76:595:45Waxing Crescent13Wed
14Thu3:479.13:547.310:411.510:321.46:585:46Waxing Crescent14Thu
15Fri4:249.45:136.511:451.211:172.26:575:47First Quarter15Fri
16Sat5:079.76:576.212:580.86:565:48First Quarter16Sat
17Sun6:009.98:456.412:153.02:150.36:545:49First Quarter17Sun
18Mon7:0310.110:037.11:323.53:26-0.26:535:50Waxing Gibbous18Mon
19Tue8:0910.310:567.72:563.74:28-0.76:525:51Waxing Gibbous19Tue
20Wed9:1410.611:408.14:083.55:22-1.16:515:52Waxing Gibbous20Wed
21Thu10:1310.95:093.26:10-1.36:505:53Waxing Gibbous21Thu
22Fri12:198.511:07 AM10.96:022.76:53-1.36:485:54Full Moon22Fri
23Sat12:568.711:59 AM10.76:522.37:33-1.06:475:55Full Moon23Sat
24Sun1:308.912:4710.27:401.98:10-0.66:465:56Full Moon24Sun
25Mon2:039.11:359.48:271.68:46-0.16:445:57Waning Gibbous25Mon
26Tue2:359.22:248.69:141.49:210.66:435:58Waning Gibbous26Tue
27Wed3:069.23:167.710:021.29:561.46:425:59Waning Gibbous27Wed
28Thu3:379.14:166.810:541.110:332.26:406:00Waning Gibbous28Thu
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9414549)

Common Questions About Upper Guadalupe Slough, CA Tides

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What time does the tide turn (slack tide) in Upper Guadalupe Slough, CA today?

Slack tide in Upper Guadalupe Slough, CA is approximately 4:21 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 Upper Guadalupe Slough, CA?

Upper Guadalupe Slough, CA is currently in a transitional phase. Tonight's moon is 37% 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 Upper Guadalupe Slough, CA 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 Upper Guadalupe Slough, CA?

Tide predictions for Upper Guadalupe Slough, CA 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 Upper Guadalupe Slough, CA?

Tide data for Upper Guadalupe Slough, CA is sourced from NOAA Station #9414549. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=9414549.

What is the moon phase in Upper Guadalupe Slough, CA tonight?

Tonight the moon over Upper Guadalupe Slough, CA is First Quarter (37% illuminated). This places Upper Guadalupe Slough, CA 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