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 7h 30m 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 - Apr 1929

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon4:358.18:296.51:050.65:536:30Third Quarter1Mon
2Tue5:417.89:236.91:273.92:150.55:526:31Third Quarter2Tue
3Wed6:557.79:587.22:483.73:160.45:506:32Third Quarter3Wed
4Thu8:047.910:257.43:453.34:050.25:496:33Waning Crescent4Thu
5Fri9:048.110:507.84:292.84:460.05:476:33Waning Crescent5Fri
6Sat9:588.411:158.25:082.35:220.05:466:34Waning Crescent6Sat
7Sun10:488.511:408.65:441.75:550.15:446:35Waning Crescent7Sun
8Mon11:378.66:211.16:290.45:436:36New Moon8Mon
9Tue12:069.112:288.56:590.47:030.85:416:37New Moon9Tue
10Wed12:349.61:208.37:40-0.27:391.35:406:38New Moon10Wed
11Thu1:0510.02:178.08:24-0.78:171.95:386:39Waxing Crescent11Thu
12Fri1:3910.23:187.69:12-0.98:592.65:376:40Waxing Crescent12Fri
13Sat2:1810.24:287.210:05-1.09:483.15:366:41Waxing Crescent13Sat
14Sun3:0410.05:477.011:06-0.910:523.55:346:42Waxing Crescent14Sun
15Mon4:019.57:097.212:15-0.75:336:42First Quarter15Mon
16Tue5:119.08:187.512:213.71:30-0.65:316:43First Quarter16Tue
17Wed6:328.69:108.01:583.42:41-0.55:306:44First Quarter17Wed
18Thu7:528.49:538.43:152.93:40-0.45:296:45Waxing Gibbous18Thu
19Fri9:048.310:298.84:162.24:30-0.25:276:46Waxing Gibbous19Fri
20Sat10:078.211:029.15:071.55:120.15:266:47Waxing Gibbous20Sat
21Sun11:048.111:329.45:530.95:500.55:256:48Waxing Gibbous21Sun
22Mon11:567.96:340.36:261.05:236:49Full Moon22Mon
23Tue12:009.512:477.77:13-0.17:001.65:226:50Full Moon23Tue
24Wed12:269.51:367.57:49-0.37:332.25:216:51Full Moon24Wed
25Thu12:519.52:257.38:25-0.58:082.75:206:51Full Moon25Thu
26Fri1:179.33:167.19:01-0.58:433.15:186:52Waning Gibbous26Fri
27Sat1:469.14:116.99:40-0.49:233.55:176:53Waning Gibbous27Sat
28Sun2:198.85:136.710:23-0.210:113.85:166:54Waning Gibbous28Sun
29Mon2:598.46:236.711:140.011:213.95:156:55Waning Gibbous29Mon
30Tue3:497.97:286.812:110.15:136:56Third Quarter30Tue
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