Manuals, Standards, Circulars and Bulletins


In this section, you will find Environment Canada's documentation pertaining to weather forecasting, observing standards, circulars and bulletins. This documentation is managed by Environment Canada for use by Environment Canada as well as for other Government of Canada Departments and partners.

Note: Clicking on the document cover image will bring you directly to the PDF version of the document. To view the document landing page and HTML versions, where available, click on the hyperlinked document title.


MANAB cover

Manual of Word Abbreviations
3rd Edition

MANICE cover

Manual of Standards and Procedures for Observing and Reporting Ice Conditions
Revised Edition

MANAIR cover

Manual of Standards and Procedures for Aviation Weather Forecasts
7th Edition

MANOBS cover

Manual of Surface Weather Observations
7th Edition, Amendment 18


Manual of Climatological Observations
4th Edition



Observer circulars provide instructions concerning new or revised observing procedures and/or new equipment and provide temporary interim instructions. Observer circulars supplement the current edition and amendment of the Manual of Surface Weather Observations - MANOBS - and are incorporated in subsequent editions or amendments.

OBS 1-2012 cover

OBS 1-2012 | PDF (accessible); 0.45 MB
Code Table (in eighths) for N, Nh and Ns
Effective December 2012

OBS 1-2013 cover

OBS 1-2013 | PDF (accessible); 0.2 MB
Eliminates the mandatory requirement for a ceiling balloon backup at stations equipped with a laser ceilometer for the determination of cloud-based heights.
Effective May 2013

OBS 1-2013 cover

OBS 2-2013 | PDF (accessible); 305 KB
Termination of recent weather (RE) codes in METAR/SPECI
Effective November 14, 2013



Aviation Weather Observing Bulletins (AVOBS) convey reminders, additional instructions, and clarification of observing procedures to weather observing stations.

AVOBS 4-2012 cover

AVOBS 4-2012 | PDF (accessible); 0.43 MB
Recording cloud traces at HWOS equipped sites
Effective December 2012

Cover image

AVOBS 1-2014 | HTML
Recording Surface Weather Observation on Form 63-2322 for stations using the NAV CANADA Human Weather Observation System
Effective February 1, 2014