Victoria, with the exception of Tasmania, is the most southerly State in Australia, which has lead to a diverse environment with many varied flora and fauna.
Melbourne has a moderate oceanic climate and is well known for its changeable weather conditions.This is mainly due to Melbourne's location situated on the boundary of the very hot inland areas and the cold southern ocean.
This temperature differential is most pronounced in the spring and summer months and can cause very strong cold fronts to form. These cold fronts can be responsible for all sorts of severe weather from gales to severe thunderstorms and hail, large temperature drops, and heavy rain.
Melbourne is prone to isolated showers These showers are often heavy and can contain hail and squalls and significant drops in temperature, but they pass through very quickly at times with a rapid clearing trend to sunny and relatively calm weather and the temperature rising back to what it was before the shower.
This occurs often in the space of minutes and can be repeated many times in a day, giving Melbourne a reputation for having "four seasons in one day" a phrase that is part of local popular culture and familiar to many visitors to the city. Its okay wait 5 minutes and it will change.
During the spring (September-November), Melbourne commonly enjoys extended periods of mild weather and clear skies. This is a great time to vist Victoria.
Melburnians also have a clever phrase "if you don't like the weather in Melbourne, just wait five minutes and it will change!". You can definitely expect changeable weather when visiting Melbourne, so make sure you pack your sunscreen and a jacket!
The BOM (Bureau of Meteorology) also have a live radar feed for Victoria. This can be very useful for comparing which way the weather is going and how it will affect your travels. It also provide marina and aeronautical updates.
It is important to plan your trip with the weather in mind. It is advised in Autumn and Winter to carry an umbrella and a sun hat in your vehicle. In Summer and Spring, keep a light jacket in case it gets cool in the evenings - there also might be some thunderstorms! Indigenous Weather Knowledge can be another source
You really can never be too sure with our unpredictable Melbourne weather! I would say from experience Febuary can be the hotest