Australia's main weather information services from the Bureau of Meteorology went down on Friday morning, affecting everything from temperature readings to radar imagery for airports.
A "major network problem" disrupted services this morning, one bureau staff member said, adding that technicians were working to fix it.
Systems are being progressively restored, a spokeswoman for the bureau said, adding that it was a "physical networking issue" and was not caused by hacking.
"Contingencies are in place to communicate severe weather information," the bureau said in a statement.
It is understood that the disruption did not affect the provision of crucial fire weather information to West Australian authorities battling blazes near Perth that have destroyed almost 100 houses.
"The bureau has contingency arrangements in place and continued to provide priority meteorological services to aviation and emergency services through the outage," the bureau said.
Last month, the ABC reported the bureau's super computer had been hacked, with China blamed as the source.
For much of the morning, temperature readings on the bureau's website were all stuck at 6am AEDT Friday, as were the radar loops. (See below). The bulk of the services are working again.
Earlier, the disruption of information affected other weather services, such as Weatherzone, although its ability to make forecasts was not impacted, Rob Sharpe, a Weatherzone meteorologist, said.
"People are left in the dark," Mr Sharpe said, adding it was fortunate the disruption had come at "one of the most benign points of the day".
The outage may have triggered "a lot more complaints" had it come a couple of days ago when wild weather was sweeping across parts of eastern Australia, with heavy rain and some flooding in the Hunter region of NSW, Mr Sharpe said.
Airports were also affected, with clients telling Weatherzone that they were not getting the usual one-minute weather updates, including the bureau's lightning data.
Sydney Airport has not reported any issues, a spokeswoman for the airport said.
"Airservices is aware that the Bureau of Meteorology is experiencing a physical networking issue which is affecting its systems," a spokeswoman for Airservices, which handles Australia's air-traffic control system, said.
"There is currently no impact to air traffic operations and we continue to work closely with the Bureau of Meteorology."