Tides Today & Tomorrow in Knappa, Knappa Slough, OR

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently falling in Knappa, Knappa Slough, OR.
Next low tide : in 3h 26m at 12:40 pm (1.4 ft)
Next high tide : 6:26 pm (7.7 ft)
Sunset today : 8:18 pm
Sunrise tomorrow : 6:17 am
Moon phase : First Quarter (37% illuminated)
Tide Station Location : Station #9439069
Common Questions About Tides

Knappa, Knappa Slough, OR Tides - May 2049

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat1:399.02:377.68:55-0.78:461.65:598:23New Moon1Sat
2Sun2:159.03:247.59:38-0.89:261.95:578:24New Moon2Sun
3Mon2:498.94:097.410:18-0.710:062.25:568:26New Moon3Mon
4Tue3:238.74:537.210:57-0.510:452.45:548:27Waxing Crescent4Tue
5Wed3:578.45:377.011:34-0.211:242.65:538:28Waxing Crescent5Wed
6Thu4:338.16:216.812:110.15:528:29Waxing Crescent6Thu
7Fri5:127.67:086.712:072.712:500.45:508:31Waxing Crescent7Fri
8Sat5:587.27:576.612:552.81:330.75:498:32First Quarter8Sat
9Sun6:566.78:476.71:542.82:241.05:478:33First Quarter9Sun
10Mon8:066.39:376.93:022.73:201.25:468:34First Quarter10Mon
11Tue9:246.010:237.24:122.34:161.45:458:36First Quarter11Tue
12Wed10:386.111:057.65:151.75:101.55:448:37Waxing Gibbous12Wed
13Thu11:446.311:458.16:101.15:591.65:428:38Waxing Gibbous13Thu
14Fri12:416.76:590.46:471.85:418:39Waxing Gibbous14Fri
15Sat12:238.51:347.07:46-0.27:331.95:408:41Full Moon15Sat
16Sun1:028.92:247.28:32-0.78:192.15:398:42Full Moon16Sun
17Mon1:429.33:147.49:18-1.09:072.25:388:43Full Moon17Mon
18Tue2:249.54:037.510:04-1.39:552.25:378:44Full Moon18Tue
19Wed3:099.54:527.510:50-1.310:452.25:368:45Waning Gibbous19Wed
20Thu3:589.35:427.511:37-1.211:382.25:358:46Waning Gibbous20Thu
21Fri4:508.96:337.512:25-0.95:348:47Waning Gibbous21Fri
22Sat5:488.47:267.612:352.11:16-0.55:338:49Third Quarter22Sat
23Sun6:537.78:207.71:402.02:10-0.15:328:50Third Quarter23Sun
24Mon8:057.19:157.92:511.83:080.45:318:51Third Quarter24Mon
25Tue9:226.710:088.24:031.44:070.85:308:52Third Quarter25Tue
26Wed10:376.510:578.55:110.85:041.25:298:53Waning Crescent26Wed
27Thu11:456.611:438.76:110.25:571.55:298:54Waning Crescent27Thu
28Fri12:456.87:05-0.36:471.85:288:55Waning Crescent28Fri
29Sat12:268.91:387.07:54-0.67:342.05:278:56New Moon29Sat
30Sun1:068.92:267.28:39-0.88:192.35:278:57New Moon30Sun
31Mon1:448.83:127.29:21-0.89:032.45:268:58New Moon31Mon
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9439069)

Common Questions About Knappa, Knappa Slough, OR Tides

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What time does the tide turn (slack tide) in Knappa, Knappa Slough, OR today?

Slack tide in Knappa, Knappa Slough, OR is approximately 3:33 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 Knappa, Knappa Slough, OR?

Knappa, Knappa Slough, OR 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 Knappa, Knappa Slough, OR 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 Knappa, Knappa Slough, OR?

Tide predictions for Knappa, Knappa Slough, OR 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 Knappa, Knappa Slough, OR?

Tide data for Knappa, Knappa Slough, OR is sourced from NOAA Station #9439069. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=9439069.

What is the moon phase in Knappa, Knappa Slough, OR tonight?

Tonight the moon over Knappa, Knappa Slough, OR is First Quarter (37% illuminated). This places Knappa, Knappa Slough, OR 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