Perth's extreme temperatures on Monday forced iiNet to shut down servers in its datacentre located in the Western Australia capital.
iiNet's chief technology officer Mark Dioguardi said in a statement on Tuesday that there was a partial failure of the mains and backup air-conditioning systems that resulted in iiNet needing to shut down some of its servers in the Perth-based datacentre at 1pm WST.
"Network redundancy plans ensured over 98 percent of our customers' broadband services were unaffected; however, some customers experienced issues connecting to the internet. Webmail and account management systems also operated intermittently during the period. A majority of the issues causing customer impact were resolved at approximately 8pm WST," he said.
iiNet call queues were closed for 40 minutes after 6pm WST on Monday while the company resolved issues with customer support systems, Dioguardi said.
"We are conducting a full investigation into this event and putting systems in place to avoid this happening in the future. iiNet apologises to our customers for any inconvenience caused."
Monday was Perth's sixth hottest day on record, reaching 44.4 degrees Celsius just before 2pm WST.
It was also the city's hottest January day since January 31, 1991.