Tides Today & Tomorrow in Upper Guadalupe Slough, CA

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Upper Guadalupe Slough, CA.
Next low tide (tomorrow) : 1:27 am (1.3 ft)
Next high tide : in 5h 31m at 5:34 pm (9.5 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 - May 1929

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed4:527.58:177.012:543.91:140.25:126:57Third Quarter1Wed
2Thu6:067.28:527.42:143.62:120.35:116:58Third Quarter2Thu
3Fri7:217.19:217.83:123.03:030.35:106:59Third Quarter3Fri
4Sat8:307.29:498.33:582.43:480.45:097:00Waning Crescent4Sat
5Sun9:347.410:168.84:391.74:280.65:087:00Waning Crescent5Sun
6Mon10:347.610:449.45:180.95:070.95:077:01Waning Crescent6Mon
7Tue11:327.711:1510.05:580.05:451.45:067:02New Moon7Tue
8Wed12:297.86:40-0.76:251.95:057:03New Moon8Wed
9Thu1:277.97:24-1.37:082.45:047:04New Moon9Thu
10Fri12:2510.82:267.88:10-1.77:532.95:037:05New Moon10Fri
11Sat1:0610.93:287.89:00-1.88:443.25:027:06Waxing Crescent11Sat
12Sun1:5310.74:327.79:54-1.79:433.55:017:07Waxing Crescent12Sun
13Mon2:4610.25:387.710:53-1.410:583.65:007:08Waxing Crescent13Mon
14Tue3:479.46:417.911:57-1.04:597:08First Quarter14Tue
15Wed4:588.67:388.212:283.41:02-0.64:587:09First Quarter15Wed
16Thu6:187.98:278.61:553.02:05-0.24:577:10First Quarter16Thu
17Fri7:407.49:089.03:072.33:000.24:577:11Waxing Gibbous17Fri
18Sat8:567.19:459.44:061.53:490.64:567:12Waxing Gibbous18Sat
19Sun10:057.110:179.74:570.84:321.24:557:13Waxing Gibbous19Sun
20Mon11:077.110:479.85:410.25:121.74:547:13Waxing Gibbous20Mon
21Tue12:037.16:20-0.25:502.24:547:14Full Moon21Tue
22Wed12:557.26:57-0.56:272.74:537:15Full Moon22Wed
23Thu1:447.37:31-0.77:043.14:527:16Full Moon23Thu
24Fri12:099.72:307.38:05-0.87:413.54:527:17Full Moon24Fri
25Sat12:399.63:167.28:40-0.88:203.74:517:17Waning Gibbous25Sat
26Sun1:129.34:027.29:17-0.79:023.84:517:18Waning Gibbous26Sun
27Mon1:499.04:497.19:57-0.69:503.94:507:19Waning Gibbous27Mon
28Tue2:308.65:377.110:41-0.410:523.94:507:20Waning Gibbous28Tue
29Wed3:178.16:237.211:28-0.24:497:20Third Quarter29Wed
30Thu4:137.67:057.512:083.812:180.04:497:21Third Quarter30Thu
31Fri5:207.17:417.91:253.41:100.34:487:22Third Quarter31Fri
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 9:30 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 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