Bureau of Meteorology


The BOM Blog gives you the background and insider info on weather, climate, oceans, water and space weather—as well as the latest on the work of the Bureau.


We welcome participation in the comments section of our blog; however, we are not able to respond to all comments and questions and your comments may take a little time to appear. The blog is monitored from 9 am to 5 pm Monday–Friday.

Our community includes people of all ages and backgrounds and we want this to be a safe and respectful environment for all. To keep the discussion interesting and relevant, please:

  • respect other people and their opinions;
  • keep your comments on topic and succinct;
  • say why you disagree or agree with someone;
  • comment constructively—in a way that adds value to the discussion.

When commenting, please don't:

  • make defamatory, libellous, false or misleading comments;
  • use obscene, insulting, racist, sexist or otherwise discriminatory or offensive language;
  • post personal information about yourself or others, such as private addresses or phone numbers;
  • promote commercial interests;
  • violate the intellectual property rights of others;
  • violate any laws or regulations;
  • provoke others, distort facts or misrepresent the views of others; or
  • post multiple versions of the same view or make excessive postings on a particular issue.

We won’t publish comments that are not in line with these standards. Blocking/removal of content or banning of users is at our discretion.

There is no endorsement, implied or otherwise, by the Bureau of any material in the comments section. Users are fully responsible for the content they submit.

Commenting is available via a Facebook plugin, which can only be accessed by those with Facebook accounts.

You can contact us at bomblog@bom.gov.au.

Copyright | Disclaimer | Privacy


Contact our social media team at socialmedia@bom.gov.au

Flagging a reliable system for early weather watchers

Flagging a reliable system for early weather watchers

Weather forecasting has always been an inventive art. No more so than during the 1930s, when a young messenger named Tom Hall would scale the roof of the Bureau's headquarters in Carlton, Melbourne, each morning to run up a series of flags denoting the day's weather.

The system of nautical-style flags was launched in late 1911—less than four years after the Bureau's formation—by Commonwealth Meteorologist, Henry A. Hunt, who would personally issue the forecast according to the day's meteorological bulletin. When he retired in 1931, Hunt's forecast 'strike rate' was estimated at an impressive 87 per cent.

Weather flags were arguably Australia's first 'real-time' weather warning system, which also included weather maps in most daily newspapers. As well as at Bureau offices in state capitals, flags were flown from the roofs of post offices, customs houses, and major newspaper offices.

Based upon an international standard pioneered in the United States, the system used a combination of six flags to signal various weather types, from fine conditions to rain, rising or falling temperatures to cool changes, or—with a prominent inner red square—heat waves.

Bureau offices would wire the day's forecast to participating buildings by 10 am each morning, with instructions as to which flags were to be hoisted and the order in which they should appear on their masts.

Cards explaining the combinations and juxtapositions of flags were made available to the public through post offices, shops and other buildings where weather forecasts were usually displayed.

Chart explaining weather flag signals that indicate the day's weather.

Weather flags were intended to promote public use of the Bureau's forecasting services—and to reduce reliance on folklore and unofficial forecasters who often charged fees for less reliable predictions.

When they were phased out in the late 1940s, the flags left a gap in tall-building weather warning systems that was eventually replaced by weather beacons—used most prominently during the 1950s and '60s to signal local weather in a code of coloured or flashing lights. 

Comment. Tell us what you think of this article.

Share. Tell others.