Get Monthly Means
noaa_marine_get_monthly_meansVerified monthly means for a CO-OPS water-level station, one row per station-month: the month's highest and lowest water, its tidal datums (MHHW, MHW, MSL, MTL, MLW, MLLW, DTL), tidal ranges (GT, MN, DHQ, DLQ), and lunitidal intervals (HWI, LWI) — the record a sea-level or tidal-range trend over years to decades is read from. Heights are relative to the requested datum in the requested units. A value CO-OPS publishes no figure for is omitted rather than reported as zero; a Great Lakes station carries only highest, msl, and lowest. A range may span up to 73,000 days, checked before the call, and CO-OPS verifies this product monthly, for the prior month, so a window ending on or after the first day of the prior month can fail with verified_data_lag. A range whose months fit the response budget is returned whole; a longer one returns the leading months, with rows_matched, rows_returned, and next_offset reporting how many matched and which offset reaches the rest. Use noaa_marine_find_stations with types=["water_level"] first to resolve a station name or location to a station ID.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| datum | No | Datum the monthly heights are referenced to. MLLW (default) is the US nautical chart datum; MHHW, MHW, MTL, MSL, and MLW are the other tidal planes. NAVD is NAVD88 and reads only where the station has an NAVD88 tie. STND is the station's own datum and reads any station. IGLD and LWD apply at Great Lakes stations only, which carry no tidal datum, and CRD at Columbia River stations only. A datum this station does not carry comes back as datum_unavailable. | MLLW |
| limit | No | Maximum months to return on this page, for a caller that wants fewer than the response budget allows. Omit for the largest page that fits; a value larger than the budget allows does not widen the page. | |
| units | No | Unit system for the heights: english = feet; metric = meters. The lunitidal intervals are hours either way. | english |
| offset | No | Month offset into the matched series, for reading a range whose months do not fit one response. 0 (default) starts at the first month; pass the next_offset from a previous call to continue. An offset past the last month returns an empty page rather than an error. | |
| end_date | Yes | End date (inclusive), YYYYMMDD or YYYY-MM-DD, e.g. "20251231" or "2025-12-31". The month it falls in is the last month returned. | |
| begin_date | Yes | Start date, YYYYMMDD or YYYY-MM-DD, e.g. "19750101" or "1975-01-01". The month it falls in is the first month returned. | |
| station_id | Yes | CO-OPS water-level station ID (numeric, e.g. "9447130" for Seattle). Obtain from noaa_marine_find_stations with types=["water_level"]. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| datum | No | Datum the heights are referenced to — echoed for correct interpretation. | |
| error | No | Present when the call failed. Absent on success. | |
| units | No | Height units: "english" (feet) or "metric" (meters). | |
| months | No | One row per station-month in the requested range, oldest first — the whole matched series when it fits one response, otherwise the leading page starting at offset. rows_matched and next_offset report what a page left behind. | |
| notice | No | What this page of the monthly series covers and how to reach the next page. | |
| end_date | No | End of the requested range as sent to CO-OPS, YYYYMMDD. | |
| truncated | No | True when this page stops short of the last matched month, so further months remain at next_offset. False on the final page and on a page past the end. Absent when the whole matched series was returned. | |
| begin_date | No | Start of the requested range as sent to CO-OPS, YYYYMMDD. | |
| station_id | No | Station ID echoed from the request — for chaining. | |
| next_offset | No | Offset to pass as offset on the next call, or null when this page reaches the last matched month. Absent when the whole matched series was returned. | |
| page_offset | No | Month offset this page starts at, echoed from the request. Absent when the whole matched series was returned. | |
| rows_matched | No | Months the requested range matched, before the page was cut. Absent when the whole matched series was returned. | |
| station_name | No | Station name as returned by CO-OPS. | |
| rows_returned | No | Months this page carries — the length of months. Absent when the whole matched series was returned. |