There are lots of weather sources and some of them are probably right, some of the time.
The BOM site has an Australian Climate Outlook at http://www.bom.gov.au/climate/outlooks/#/temperature/summary which states: “the country has roughly equal chances of a warmer or cooler than average three months.” Thanks BOM!
Weather2 is one of the other weather sites and they provide a Mount Hotham 14 day Forecast. Their prediction may be accurate but overall it they predict warmer temperatures than the BOM.
YR is another weather site and they provide a 3 day forecast for the Alpine National Park Bogong area (https://www.yr.no/place/Australia/Victoria/Alpine_National_Park_Bogong_Unit/).
There is another site that have very good visualisations of the whole country. Check it out at https://www.windy.com/?temp,-36.794,147.245,12https://www.windy.com/?temp,-36.794,147.245,12
There are a few webcams available in the area we are walking in. They are not close enough to see anything except what the current weather is doing. The best of the webcams is of Mount Hotham (Mt Hotham Webcam).
2018 Trek Weather Report
We had a range of weather on the trek but overall it was excellent.
Our first night in tents, at Mountain Creek Camping Ground, had light rain for most of the night. Monday we experienced light rain and foggy clounds all the way up Mt Bogong. It was cold weather but we were all hot from exertion. When we finally got above the treeline, the wind increased and the temperature decreased. The wind was gusting somewhere near 70km/hour and the temperature dropped and was close to zero. The next morning was still a llittle foggy but this decreased during the morning and we enjoyed increasingly warmer weather for the rest of the week. Temperatures weren’t overly warm and that made it excellent for hiking. Most of us were able to wear shorts and t-shirts for much of the walk and this was comfortable atire. Thursday was colder than Wednesday and Friday.