Can you post a screenshot? If you click into the individual site it is only every 30 min. If you stay on the general Syd Observations page it is all sites updated every 10 minutes (generally at 2:34pm for data up to 2:30 etc.)
Here you go. Just need to look in the correct column
http://www.bom.gov.au/nsw/observations/sydney.shtml?ref=hdr