What you need
- Multimeter for macOS 13 or later, $19.99 once.
- A station id from tidesandcurrents.noaa.gov (find your station on the map; the id is a 7 digit number, like 9414290 for San Francisco).
Set it up
- Add a Web Address meter with your station in this address and the key path
data.0.v:Web addresshttps://api.tidesandcurrents.noaa.gov/api/prod/datagetter?date=latest&station=9414290&product=water_level&datum=MLLW&units=english&time_zone=lst_ldt&format=json - Refresh every 15 minutes. Set the range to the station’s usual span (for San Francisco, -1 to 7 feet) and the unit to
ft.
Multimeter settings
In Customize This Meter… (from the meter’s menu):
| Setting | Value |
|---|---|
| Source | Web Address |
| Web address | the NOAA address above with your station |
| Key path | data.0.v |
| Refresh every | 15 minutes |
| Range | like -1 to 7 |
| Unit | ft |
| Label | TIDE |
| Face | Oscilloscope, Sparkline or Level Bar |
Tested: Run on October 29, 2026: San Francisco 4.755 ft, The Battery (New York, 8518750) 5.157 ft; water temperature at The Battery 60.6 °F.
More on this source, including every format it reads, in the Web Address guide.
Limits
- US stations only. Heights are relative to the station’s datum (MLLW: mean lower low water), so 0 is a low tide, not sea level.
Variations
Metric
Use units=metric and the unit m.
Water temperature
product=water_temperature (drop &datum=MLLW), key path data.0.v. Not every station has a thermometer.
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| No number found in the response | The key path doesn’t match the reply. | Run curl -s with the address and read the JSON. Dots walk into objects, numbers pick array items (items.0.count). |
| Couldn’t reach the address | No network, a typo in the host, or the service is down. | Open the address in your browser. Multimeter tries again at the next refresh. |
| No number found | The reply is an error object: the station doesn’t report that product. | Open the address in a browser to read the error; try a nearby station. |
Questions
Can it show the predicted next high tide?
The predictions product returns a list of times; a Script meter with jq could count minutes to the next one. The water level is the simple, live number.