How to read a tide chart
A tide chart, sometimes called a tide level chart, draws the predicted height of the sea through the day as one curve. This guide shows how to read tide charts with a real example rather than a drawing: the predicted tide in La Jolla on Tuesday, October 6. Predictions from NOAA station Scripps Pier, near La Jolla. The example and every number in it are refreshed each week from new NOAA predictions, so the figures below will not match a printed tide table from another week.
The same steps work for how to read the tide chart on any of our place pages, and the last two sections explain the weekly tide table and the monthly calendar those pages carry.
Reading a tide chart step by step
Predicted tide at Scripps Pier on Tuesday, October 6: lower low −0.2 ft at 12:59 AM, lower high 4.7 ft at 7:35 AM, higher low 1.8 ft at 1:02 PM, higher high 5.5 ft at 6:56 PM. Tidal range 5.7 ft. Sunrise 6:47 AM, sunset 6:27 PM. The 12:59 AM low (−0.2 ft) dips into the band but comes before sunrise, so it does not count as a tide pool window. The 1:02 PM low (1.8 ft) stays above the band, even though it comes in daylight.
Heights in feet above mean lower low water (MLLW). Shaded parts are night. The strip under the curve shows rising (blue) and falling (white) water. Orange points are daylight low tides in the tide pool band.
- Check the place, the station and the date. A tide chart is a prediction for one NOAA station on one day. This one is for Tuesday, October 6, and the station is Scripps Pier, which NOAA lists as La Jolla (Scripps Institution Wharf).
- Read the height scale. The numbers on the left are feet above MLLW, the average low water level explained below. That day the water reaches 5.5 ft at its highest and −0.2 ft at its lowest.
- Read the time scale. The bottom axis runs from midnight to midnight in Pacific time, with daylight saving time when it applies. The shaded ends of the chart are night: sunrise is at 6:47 AM and sunset at 6:27 PM.
- Find the highs and lows. Each peak of the curve is a high tide and each dip a low tide. Going from midnight, the day brings a lower low of −0.2 ft at 12:59 AM, a lower high of 4.7 ft at 7:35 AM, a higher low of 1.8 ft at 1:02 PM and a higher high of 5.5 ft at 6:56 PM.
- Follow the slope. Between a low and the next high the water is rising (the blue parts of the strip under the curve); between a high and the next low it is falling. The biggest move starting that day is the falling tide from 6:56 PM to 1:37 AM the next day: the water drops 5.6 ft in 6 h 41 min.
- Check the tide pool band. The orange band covers 1.0 ft and lower. The 12:59 AM low (−0.2 ft) dips into the band but comes before sunrise, so it does not count as a tide pool window. The 1:02 PM low (1.8 ft) stays above the band, even though it comes in daylight.
| Part of the chart | On this day | What it tells you |
|---|---|---|
| Lower low | 12:59 AM, −0.2 ft | The lowest water of the day. MLLW is the long-term average of this tide. |
| Lower high | 7:35 AM, 4.7 ft | The smaller of the two high tides. |
| Higher low | 1:02 PM, 1.8 ft | The shallower of the two low tides. |
| Higher high | 6:56 PM, 5.5 ft | The highest water of the day. |
| Tidal range | 5.7 ft | Highest high minus lowest low: how far the water moves up and down that day. |
| Sunrise and sunset | 6:47 AM and 6:27 PM | The shaded night is outside these times. A tide pool window has to fall between them. |
| Tide pool band | 1.0 ft and lower | Our rule: a daylight low tide at 1.0 ft or lower is a tide pool window; at 0.0 ft or lower it is rated very good. |
High tide, low tide and tidal range
NOAA describes the tide as a very long wave: high tide is when its crest reaches the coast and low tide is when its trough does. The tidal range is simply the height difference between a high tide and a low tide. On a chart, you read it as the vertical distance between a peak and a dip. On Tuesday, October 6 the range from the highest to the lowest point at Scripps Pier is 5.7 ft.
California tides rarely come in matching pairs. According to NOAA, the US West Coast usually has mixed semidiurnal tides: two highs and two lows a day, but of different heights. That is why our charts call them the higher high and lower high, and the higher low and lower low. On Tuesday, October 6, the two highs at Scripps Pier are 0.8 ft apart and the two lows 2.0 ft apart.
The tides follow the moon, not the clock. NOAA gives the lunar day as 24 hours and 50 minutes, with high tides about 12 hours and 25 minutes apart, so each tide comes back later the next day. In the La Jolla predictions, the higher high of 6:56 PM on Tuesday, October 6 comes back at 7:46 PM on Wednesday, October 7, 50 minutes later than the day before.
The range changes through the month as well. NOAA explains that around new and full moon the sun and moon pull together, which makes high tides a little higher and low tides a little lower (spring tides); about a week later, at the quarter moons, the range shrinks (neap tides). Between October 1 and October 30, the daily range at Scripps Pier runs from 1.1 ft on Monday, October 19 (moon: waxing gibbous) to 7.4 ft on Tuesday, October 27, two days after the full moon of October 25. Each place page names the week's biggest swing above its weekly tide table, as on the La Jolla tide chart.
One limit applies to every tide chart on this site: it shows the astronomical tide. As NOAA points out, tide predictions cannot include the effect of wind, air pressure or river flow, which can raise or lower the real water level, sometimes by a lot.
What negative tides and MLLW mean
Every height on a tide chart is measured from a zero line called a datum. In the United States, tide predictions use MLLW, mean lower low water: for each day, take the lower of the two low tides, and average it over NOAA's 19-year reference period, 1983 to 2001. NOAA uses the same zero for its nautical charts (NOAA tidal datums).
Zero, then, is an ordinary low tide for that station. Because it is an average, some lower lows end up below it, and those print as negative numbers. A negative tide, or minus tide, is a lower than average low tide. Between October 1 and October 30, 10 low tides at Scripps Pier go below 0.0 ft. The lowest is −0.8 ft on Tuesday, October 27 at 4:57 PM, in daylight. Of these, 5 fall in daylight.
For tide pooling, the lower the better, as long as it is light out. In the same 30 days, 12 daylight low tides reach our tide pool band of 1.0 ft or lower. The La Jolla tide chart lists them with their ratings.
Each station has its own MLLW, so the same number does not mean the same water level at two places. Compare tides within one place, not between them. The table shows the lowest predicted tide at each of our places over the same 30 days. Every one of our 12 places has at least one negative low tide in that period. The lowest is −1.2 ft at Half Moon Bay on Wednesday, October 28.
| Place | NOAA station | Lowest tide | When |
|---|---|---|---|
| San Francisco tide chart | Golden Gate | −1.1 ft | Wednesday, October 28, 7:52 PM, dark |
| Half Moon Bay tide chart | Pillar Point Harbor | −1.2 ft | Wednesday, October 28, 7:21 PM, dark |
| Santa Cruz tide chart | Santa Cruz | −0.9 ft | Wednesday, October 28, 7:09 PM, dark |
| Monterey tide chart | Monterey | −0.9 ft | Wednesday, October 28, 7:20 PM, dark |
| Pismo Beach tide chart | Port San Luis | −0.8 ft | Wednesday, October 28, 6:53 PM, dark |
| Santa Barbara tide chart | Santa Barbara | −0.8 ft | Tuesday, October 27, 5:30 PM, daylight |
| Malibu tide chart | Santa Monica Pier | −0.9 ft | Tuesday, October 27, 5:08 PM, daylight |
| Huntington Beach tide chart | Balboa Pier | −0.8 ft | Tuesday, October 27, 5:03 PM, daylight |
| Newport Beach tide chart | Newport Bay Entrance | −0.8 ft | Tuesday, October 27, 4:59 PM, daylight |
| Laguna Beach tide chart | San Clemente | −0.7 ft | Tuesday, October 27, 4:49 PM, daylight |
| La Jolla tide chart | Scripps Pier | −0.8 ft | Tuesday, October 27, 4:57 PM, daylight |
| San Diego tide chart | San Diego Bay (Broadway) | −0.8 ft | Tuesday, October 27, 5:00 PM, daylight |
Heights in feet above each station's MLLW. "Dark" means before sunrise or after sunset.
How to read our weekly tide table
Every place page has a seven-day tide table under a seven-day curve. Below are the real ones from theLa Jolla tide chart. In the table, each row is one day. Low tides come first, in bold blue, because this site is built around low tides; high tides follow. Each entry gives the time and the height. The first row, Thursday, October 1, lists two lows, 2.5 ft at 5:25 AM and 0.3 ft at 8:17 PM, and two highs, 3.2 ft at 1:29 AM and 5.7 ft at 12:18 PM.
October 4 has fewer than four tides: because the tides come about 50 minutes later each day, now and then a high or low slips past midnight into the next date. The sunrise and sunset columns let you see at a glance whether a low tide falls in daylight, and the moon column gives the phase, which hints at the size of the swing (bigger near new and full moon). An orange dot marks a daylight low tide in the tide pool range; there is none in these 7 days, so no row has one.
The curve draws the same predictions as one line across the week, with night shaded, so you can spot the lowest dips and when they come. The short summary just below is written from the same numbers each week.
From October 1 to October 7, the lowest tide in La Jolla is −0.2 ft on Tuesday, October 6, at 12:59 AM, after dark.
None of these days has a daylight low tide of 1.0 ft or lower; the lowest one is 1.2 ft on Wednesday, October 7, at 1:49 PM.
The biggest swing is on Tuesday, October 6, 5.7 ft between high and low water; the highest tide is 5.7 ft on Thursday, October 1, at 12:18 PM.
Predicted tide from Thursday, October 1 to Wednesday, October 7. The water ranges from −0.2 ft on Tuesday, October 6, at 12:59 AM to 5.7 ft on Thursday, October 1, at 12:18 PM. No low tide reaches the tide pool range (1.0 ft or lower) in daylight.
Shaded parts are night. The orange band is the tide pool range; orange points are daylight tide pool lows.
| Date | Low tides | High tides | Sunrise | Sunset | Moon |
|---|---|---|---|---|---|
| Thu 1 | 5:25 AM, 2.5 ft8:17 PM, 0.3 ft | 1:29 AM, 3.2 ft12:18 PM, 5.7 ft | 6:43 AM | 6:33 PM | Waning gibbous, 70% lit |
| Fri 2 | 5:57 AM, 3.0 ft9:53 PM, 0.3 ft | 3:53 AM, 3.0 ft1:25 PM, 5.4 ft | 6:44 AM | 6:32 PM | Waning gibbous, 59% lit |
| Sat 3 | 8:11 AM, 3.3 ft11:14 PM, 0.1 ft | 6:08 AM, 3.4 ft3:02 PM, 5.2 ft | 6:45 AM | 6:31 PM | Last quarter at 6:25 AM |
| Sun 4 | 10:45 AM, 3.1 ft | 6:40 AM, 3.8 ft4:41 PM, 5.2 ft | 6:45 AM | 6:29 PM | Waning crescent, 36% lit |
| Mon 5 | 12:14 AM, −0.1 ft12:06 PM, 2.5 ft | 7:08 AM, 4.2 ft5:57 PM, 5.4 ft | 6:46 AM | 6:28 PM | Waning crescent, 26% lit |
| Tue 6 | 12:59 AM, −0.2 ft1:02 PM, 1.8 ft | 7:35 AM, 4.7 ft6:56 PM, 5.5 ft | 6:47 AM | 6:27 PM | Waning crescent, 17% lit |
| Wed 7 | 1:37 AM, −0.1 ft1:49 PM, 1.2 ft | 8:02 AM, 5.1 ft7:46 PM, 5.5 ft | 6:48 AM | 6:26 PM | Waning crescent, 9% lit |
Daylight low tide good for tide pools. Heights in feet above mean lower low water (MLLW).
How to read the monthly tide calendar
The monthly calendar answers one question for each day: how low does the water get while it is light? Each square shows that day's lowest daylight low tide in feet, with its time on wider screens. A darker blue means a lower tide, so the best weeks stand out before you read a single number. Days with a tide pool window turn orange. In November, 13 days are orange, 9 of them in the stronger orange for very good. The month's lowest daylight tide is −1.5 ft on Wednesday, November 25 at 3:55 PM.
The calendar leaves out night-time lows and all high tides; for those, use the weekly table above or the place page. These are the real La Jolla calendars for this month and next.
Each day shows its lowest low tide between sunrise and sunset, in feet. The deeper the blue, the lower that tide. Orange days have a tide pool window; the stronger orange ones are rated very good.
| Sun | Mon | Tue | Wed | Thu | Fri | Sat |
|---|---|---|---|---|---|---|
| Thursday, October 1: no low tide in daylight | Friday, October 2: no low tide in daylight | Saturday, October 3: lowest daylight tide 3.3 ft at 8:11 AM | ||||
| Sunday, October 4: lowest daylight tide 3.1 ft at 10:45 AM | Monday, October 5: lowest daylight tide 2.5 ft at 12:06 PM | Tuesday, October 6: lowest daylight tide 1.8 ft at 1:02 PM | Wednesday, October 7: lowest daylight tide 1.2 ft at 1:49 PM | Thursday, October 8: lowest daylight tide 0.6 ft at 2:31 PM, good tide pool window | Friday, October 9: lowest daylight tide 0.3 ft at 3:11 PM, good tide pool window | Saturday, October 10: lowest daylight tide 0.0 ft at 3:49 PM, very good tide pool window |
| Sunday, October 11: lowest daylight tide −0.1 ft at 4:27 PM, very good tide pool window | Monday, October 12: lowest daylight tide 0.0 ft at 5:06 PM, very good tide pool window | Tuesday, October 13: lowest daylight tide 0.2 ft at 5:47 PM, good tide pool window | Wednesday, October 14: no low tide in daylight | Thursday, October 15: no low tide in daylight | Friday, October 16: no low tide in daylight | Saturday, October 17: no low tide in daylight |
| Sunday, October 18: lowest daylight tide 3.5 ft at 9:40 AM | Monday, October 19: lowest daylight tide 3.1 ft at 11:31 AM | Tuesday, October 20: lowest daylight tide 2.6 ft at 12:20 PM | Wednesday, October 21: lowest daylight tide 2.0 ft at 12:58 PM | Thursday, October 22: lowest daylight tide 1.4 ft at 1:33 PM | Friday, October 23: lowest daylight tide 0.7 ft at 2:09 PM, good tide pool window | Saturday, October 24: lowest daylight tide 0.1 ft at 2:47 PM, good tide pool window |
| Sunday, October 25: lowest daylight tide −0.4 ft at 3:27 PM, very good tide pool window | Monday, October 26: lowest daylight tide −0.7 ft at 4:10 PM, very good tide pool window | Tuesday, October 27: lowest daylight tide −0.8 ft at 4:57 PM, very good tide pool window | Wednesday, October 28: lowest daylight tide −0.8 ft at 5:51 PM, very good tide pool window | Thursday, October 29: no low tide in daylight | Friday, October 30: no low tide in daylight | Saturday, October 31: no low tide in daylight |
October has 12 tide pool days, 7 rated very good. The lowest daylight tide is −0.8 ft on Tuesday, October 27 at 4:57 PM.
| Sun | Mon | Tue | Wed | Thu | Fri | Sat |
|---|---|---|---|---|---|---|
| Sunday, November 1: lowest daylight tide 3.1 ft at 7:55 AM | Monday, November 2: lowest daylight tide 2.7 ft at 9:49 AM | Tuesday, November 3: lowest daylight tide 2.0 ft at 11:04 AM | Wednesday, November 4: lowest daylight tide 1.3 ft at 12:00 PM | Thursday, November 5: lowest daylight tide 0.6 ft at 12:47 PM, good tide pool window | Friday, November 6: lowest daylight tide 0.1 ft at 1:28 PM, good tide pool window | Saturday, November 7: lowest daylight tide −0.2 ft at 2:06 PM, very good tide pool window |
| Sunday, November 8: lowest daylight tide −0.4 ft at 2:42 PM, very good tide pool window | Monday, November 9: lowest daylight tide −0.5 ft at 3:18 PM, very good tide pool window | Tuesday, November 10: lowest daylight tide −0.4 ft at 3:54 PM, very good tide pool window | Wednesday, November 11: lowest daylight tide −0.2 ft at 4:32 PM, very good tide pool window | Thursday, November 12: no low tide in daylight | Friday, November 13: no low tide in daylight | Saturday, November 14: no low tide in daylight |
| Sunday, November 15: no low tide in daylight | Monday, November 16: lowest daylight tide 3.3 ft at 7:20 AM | Tuesday, November 17: lowest daylight tide 3.0 ft at 9:32 AM | Wednesday, November 18: lowest daylight tide 2.4 ft at 10:44 AM | Thursday, November 19: lowest daylight tide 1.7 ft at 11:33 AM | Friday, November 20: lowest daylight tide 1.0 ft at 12:15 PM, good tide pool window | Saturday, November 21: lowest daylight tide 0.2 ft at 12:56 PM, good tide pool window |
| Sunday, November 22: lowest daylight tide −0.5 ft at 1:38 PM, very good tide pool window | Monday, November 23: lowest daylight tide −1.1 ft at 2:21 PM, very good tide pool window | Tuesday, November 24: lowest daylight tide −1.4 ft at 3:06 PM, very good tide pool window | Wednesday, November 25: lowest daylight tide −1.5 ft at 3:55 PM, very good tide pool window | Thursday, November 26: no low tide in daylight | Friday, November 27: no low tide in daylight | Saturday, November 28: no low tide in daylight |
| Sunday, November 29: no low tide in daylight | Monday, November 30: lowest daylight tide 2.7 ft at 7:48 AM |
November has 13 tide pool days, 9 rated very good. The lowest daylight tide is −1.5 ft on Wednesday, November 25 at 3:55 PM.
Common questions about tide charts
How do you read a tide chart?
Read the curve against its two scales: the height of the water in feet on the vertical axis and the time of day on the horizontal one. Peaks are high tides, dips are low tides, and the curve between them shows the water rising or falling. On Tuesday, October 6 the La Jolla chart above shows a lower low of −0.2 ft at 12:59 AM, a lower high of 4.7 ft at 7:35 AM, a higher low of 1.8 ft at 1:02 PM and a higher high of 5.5 ft at 6:56 PM, so the water moves 5.7 ft from its highest to its lowest point.
What does a negative tide mean?
It means the water is predicted to drop below 0.0 ft, the average height of the day's lowest tide (MLLW). A negative low tide is lower than average and uncovers more of the shore than usual, which is why the lowest ones are the best for tide pools when they come in daylight. Between October 1 and October 30, 10 low tides at Scripps Pier go below 0.0 ft. The lowest is −0.8 ft on Tuesday, October 27 at 4:57 PM, in daylight. Of these, 5 fall in daylight.
What is MLLW on a tide chart?
MLLW stands for mean lower low water: the average of the lower of each day's two low tides, measured at the station over NOAA's 19-year reference period, 1983 to 2001. NOAA uses it as the zero point for tide predictions and nautical charts, so a height of 2.0 ft on our charts means 2 feet above that average (NOAA tidal datums).
Our guide to the best tide for fishing puts these charts to work for surf, beach and pier fishing. For a place, start from the California tide charts.
Sources: NOAA tidal datums, the NOAA tides tutorial onwhat tides are, the lunar day andtidal cycles, spring and neap tides and thelimits of tide predictions. Tide predictions from NOAA CO-OPS.