Historical Observing Metadata Repository
The Historical Observing Metadata Repository (HOMR) is NCDC's integrated
station history database that provides in situ
or land-based station metadata in support of NCDC research, reporting,
data products, and web applications. HOMR tracks detailed information for
a variety of weather stations throughout their lifespans, including identifiers,
names, locations, observation times, reporting methods, photos, and equipment
modifications and siting. Station histories are most extensive for the
National Weather Service (NWS) Cooperative Observing Program, and they include
officially documented station changes that adhere to an
NWS approval process.
Use the search below to access these historical station details.
HOMR Web Service
HOMR provides a web service that you can use to get station metadata in JSON format. This page
documents the URL formats used to get the data you want. All calls to the web service should
be GET requests. The WADL for this web service can be
All queries, if they find one or more stations, will return a JSON object with the property
stationCollection, which contains a
definitions section and a stations
section. definitions contains the same information for each request: descriptive information
about the fields that can be found in a station metadata entry. stations
contains the list of stations that matched your search query. Each entry in the stations
list has an ncdcStnId, and other properties such as
names and location, depending on
what information is available for that station.
Note that very broad searches - e.g. for an entire state or network - will take a very long
time to return. Consider using the headersOnly=true
argument (documented below) when making these kinds of requests.
The base URL for the web service is located here:
If you know the unique NCDC Station ID of the station you are looking for, you can request it directly:
This will give you only the most recent values for each field. You can get the entire
station history by adding date=all
Other date options include single points in time and date ranges:
If you do not know exactly which station you are looking for, or you only know the qualified ID,
you can use the search function with various parameters:
Available Query Parameters
Any fully qualified ID such as COOP:046742
. When used with
, can contain partial station ID's. Either the network
or ID number may be omitted.
Specifies how the ID portion of the qid
parameter should be
applied within the search. If a qid
is passed but the
parameter is not used, qidMod
is assumed to be
Two-letter code for US states, Canadian provinces, and other Island areas.
US county names, best used with a state identifier.
for a list of valid country names.
Searches on any type of name we have for the station.
Specifies how the name
parameter should be applied within the search.
If a name
but the nameMod
parameter is not used,
is assumed to be IS
platform (aka network)
Limit the search to stations of a certain platform/network type.
Limits values to only those that occurred on a specific date. Alternatively,
will return all values for matched stations. If this
field is omitted, the search will return only the most recent values for each field.
Limits values to only those that occurred within a date range.
Returns only minimal information for each station found (NCDC Station ID, Preferred Name, Station Begin Date, and Station End Date), but
is much quicker than a full query. If you are performing a search that returns a large number of stations and intend to choose only
one from that list to examine in detail, headersOnly
may give you enough information to find the NCDC Station ID for the station that you
The HOMR web service now includes PHR (element-level) data when available, in an elements
section. Because of how this data is structured,
it can substantially increase the size of any result which includes it. If you don't need this data you can omit
it by including phrData=false
. If the parameter is not set, it will default to
The HOMR web service includes a list of definitions
with every result.
These are meant to serve as a reference for some of the more cryptic variable values, and are identical for every request.
You can omit these from your result by setting definitions=false