Yes

you do need a jacket based on the weather in Sydney NSW, Australia 3 minutes ago

Why? Because it's pretty chilly!
51°F10°C & Clear

Wind is 5 mph8 km/h from the West, gusting to 11 mph17 km/h
July 6
1pm51°F10°C5 mph9 km/h WestClear
2pm50°F10°C6 mph9 km/h WestClear
3pm49°F9°C6 mph9 km/h NorthwestClear
4pm48°F9°C6 mph10 km/h NorthwestClear
5pm49°F9°C7 mph11 km/h NorthwestClear
6pm49°F10°C6 mph10 km/h NorthwestMostly Clear
7pm52°F11°C7 mph11 km/h WestClear
8pm55°F13°C8 mph12 km/h WestMostly Clear
9pm58°F15°C9 mph15 km/h WestMostly Clear
10pm60°F16°C10 mph16 km/h WestMostly Clear
11pm62°F17°C11 mph17 km/h WestPartly Cloudy
July 7
12am62°F17°C10 mph17 km/h SouthwestPartly Cloudy
DateLowHighWindDayNight
July 648°F9°C63°F17°C9 mph14 km/h from WestMostly ClearMostly Clear
July 745°F7°C62°F17°C8 mph13 km/h from NorthwestMostly CloudyClear
July 849°F10°C63°F17°C6 mph9 km/h from NorthwestMostly ClearMostly Cloudy
July 950°F10°C59°F15°C14 mph22 km/h from NorthwestPartly CloudyClear
July 1046°F8°C61°F16°C11 mph17 km/h from WestClearClear
July 1147°F8°C63°F17°C6 mph10 km/h from WestClearMostly Clear
July 1245°F7°C63°F17°C7 mph12 km/h from NorthwestMostly ClearMostly Clear

Yes

Low of 46°F8°C, High of 62°F17°C
Wind: 8 mph13 km/h
Precipitation: None

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