To repeat one incident: During ‘discussions’ on the now defunct WXzone forum covering the very hot temperature records of the Victorian bush fires of 1851 Trewin made the claim that there were no official WX station in Melbourne
This in theory is correct, there was a weather station in Melbourne, it was properly equipped with devices of the day and thermometers were mounted in locations that provided consistent ambient readings. However that station shut down during 1851 and a new station in the same location not officially operating until 1858. So there are no reliable records from 1851 to 1858.
More searching showed roofing iron had only just been invented so bugger-all hot tin roofs.
Again 1851 is an odd point to pick as it's just as the Iron pre-fabs were just starting to arrive in Melbourne. Houses made completely of Iron and shipped from the UK to Victoria for makeshift housing for the goldrush. The buildings were completely wrong for the Australian climate, but about 3 still exist today. I can't get an exact date of the first arrival, but there was around 100 existing by 1855. Corrugated iron was indeed new technology, but that was during the 1830s, by the 1850s it was being mass produced for pre-fab items and shipped to places like Australia, and had already been shipped to California by the late 1840s. So the idea of an iron veranda being a thing during the 1850s is quite plausible.