Yes

you do need a jacket based on the weather in Williamstown VIC 3016, Australia 1 second ago

Why? Because the air feels like the cozy middle ground between summer and winter!
54°F12°C & Clear

Wind is 6 mph10 km/h from the Southeast, gusting to 13 mph21 km/h
August 2
5am53°F11°C5 mph7 km/h SoutheastClear
6am51°F10°C3 mph5 km/h SoutheastClear
7am49°F10°C3 mph4 km/h EastClear
8am48°F9°C3 mph5 km/h NorthwestClear
9am46°F8°C3 mph5 km/h NorthwestMostly Clear
10am45°F7°C3 mph5 km/h NorthPartly Cloudy
11am43°F6°C3 mph5 km/h NorthPartly Cloudy
12pm43°F6°C3 mph5 km/h NorthPartly Cloudy
1pm42°F5°C3 mph4 km/h NortheastPartly Cloudy
2pm41°F5°C3 mph4 km/h NortheastPartly Cloudy
3pm40°F4°C2 mph4 km/h NorthPartly Cloudy
4pm39°F4°C3 mph4 km/h NorthPartly Cloudy
DateLowHighWindDayNight
August 145°F7°C57°F14°C3 mph5 km/h from SouthwestMostly ClearMostly Clear
August 239°F4°C65°F18°C3 mph5 km/h from NortheastPartly CloudyMostly Clear
August 347°F8°C62°F16°C14 mph22 km/h from NorthMostly CloudyRain
August 448°F9°C60°F15°C9 mph14 km/h from NorthwestPartly CloudyMostly Clear
August 544°F7°C56°F13°C9 mph14 km/h from WestDrizzlePartly Cloudy
August 641°F5°C55°F13°C4 mph7 km/h from SouthwestPartly CloudyMostly Clear
August 740°F4°C56°F13°C4 mph6 km/h from SouthMostly ClearMostly Clear

Yes

Low of 39°F4°C, High of 65°F19°C
Wind: 3 mph5 km/h
Precipitation: None

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