Are you getting 403 Forbidden errors? Read the FAQ and check your User-Agent header!



Sigcharts - Significant Weather Charts for aviation


This service delivers Significant Weather Charts in PNG format, covering the Nordic area, Svalbard and the Norwegian Sea.

Charts are issued every six hours, valid for the hours 00, 06, 12 and 18 UTC. Charts for Norway are not produced during the weekend. At least 4 charts are available for each area.

For more information, see



Area can be specified as a method, e.g.



Area covered in forecast, defaults to "norway". Valid options are:

  • nordic
  • norway


Time in ISO format, e.g. "2020-12-24T12:00:00Z". If omitted, the newest available image will be served (unless the offset parameter is used).


Count back n images from newest. Valid options are from 1 to 3 (optional).

Other parameters may be added later. Stay tuned.

Sample request URLs


A list of all images can be fetched at:


All changes are available as an RSS feed at the following URL:

Version 1.0 EOL extended: 2022-06-01

The old version 1.0 has been extended to Sep 1st, 2022

Version 2.0 in production: 2022-01-04

The old version 1.0 is now deprecated, and will be terminated on June 1st, 2022

Version 2.0 beta: 2021-07-13

Added Nordic area, params made consistent with rest of API

Version 1.0: 2020-11-30

Optional parameter validdate added

Version 1.0: : 2019-11-20

Prototype version