Archived Initialization Times

Returns a list of archived initialization times (model run start times) for the specified model . Results are paginated. Use page and page_size to control pagination, and order to sort by newest or oldest first. For archived runs, only full gridded forecast data is available.

A model parameter must be provided to specify which weather model's initialization times to retrieve. You can find a list of available models here.

WM-5c file format

Archived gridded data for WM-5c from February 11, 2026 onwards is served as Zarr instead of NetCDF.

forecasts/v1/<model>/initialization_times/archiveforecasts/v1/<model>/initialization_times/archive

windborne archived_init_times windborne archived_init_times

from windborne import get_archived_initialization_timesfrom windborne import get_archived_initialization_times

Query parameters

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string
ens_member Optional	The ensemble member for which to list initialization times.	mean or 0-23

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string
ens_member Optional	The ensemble member for which to list initialization times.	mean or 0-23

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string
ens_member Optional	The ensemble member for which to list initialization times.	mean or 0-23

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description	Format
page Optional	Page number for pagination. Default: 0	integer
page_size Optional	Number of results per page. Default: 64, max 500	integer
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest	string

Name	Description
-m --model	Set to wm-5c .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
-e --ens-member Optional	The ensemble member to get initialization times for. Can be "mean" or a number between 0 and 23.

Name	Description
-m --model	Set to wm-4.5-ens .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to wm-4 .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to wm-4-ens .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
-e --ens-member Optional	The ensemble member to get initialization times for. Can be "mean" or a number between 0 and 23.

Name	Description
-m --model	Set to ecmwf-det .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to ecmwf-ens .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to aifs .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to gfs .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
-m --model	Set to hrrr .
--page Optional	Page number for pagination. Default: 0
--page-size Optional	Number of results per page. Default: 64, max 500
--order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest

Name	Description
model	Set to wm-5c .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
ens_member Optional	The ensemble member to get initialization times for. Can be "mean" or a number between 0 and 23.
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to wm-4.5-ens .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to wm-4 .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to wm-4-ens .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
ens_member Optional	The ensemble member to get initialization times for. Can be "mean" or a number between 0 and 23.
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to ecmwf-det .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to ecmwf-ens .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to aifs .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to gfs .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Name	Description
model	Set to hrrr .
page Optional	Page number for pagination. Default: 0
page_size Optional	Number of results per page. Default: 64, max 500
order Optional	Sort order: newest returns most recent first, oldest returns earliest first. Default: newest
print_response Optional	Whether to print formatted output. Default: false

Response parameters

Name	Type	Description	Format
archived_initialization_times	array	An array of ISO 8601 timestamps of available historical initialization times for point forecasts.	-
timestamp	string	ISO 8601 timestamp of an available historical initialization time	ISO 8601
total	integer	Total number of archived initialization times available across all pages.	-
page	integer	Current page number.	-
page_size	integer	Number of results per page.	-

archived_initialization_times	Array (19 items) [0]"2025-09-04T00:00:00Z" [1]"2025-09-09T18:00:00Z" [2]"2025-09-10T00:00:00Z" [3]"2025-09-10T06:00:00Z" [4]"2025-09-10T12:00:00Z" [5]"2025-09-10T18:00:00Z" [6]"2025-09-11T00:00:00Z" [7]"2025-09-11T06:00:00Z" [8]"2025-09-11T12:00:00Z" [9]"2025-09-11T18:00:00Z" [10]"2025-09-12T00:00:00Z" [11]"2025-09-12T06:00:00Z" [12]"2025-09-12T12:00:00Z" [13]"2025-09-12T18:00:00Z" [14]"2025-09-30T00:00:00Z" [15]"2025-09-30T06:00:00Z" [16]"2025-09-30T12:00:00Z" [17]"2025-09-30T18:00:00Z" [18]"2025-10-01T00:00:00Z"
total	1247
page	0
page_size	64

GET Archived Initialization Timesfree

Query parameters

Response parameters

GET Archived Initialization Times