Yes

you do need a jacket based on the weather in Sydney Olympic Park NSW 2127, Australia 1 second ago

Why? Because it's cool. Pleasantly cool, but cool!
54°F12°C & Clear

Wind is 5 mph8 km/h from the Northwest, gusting to 13 mph21 km/h
July 15
9pm54°F12°C5 mph9 km/h NorthwestClear
10pm58°F14°C5 mph9 km/h NorthwestClear
11pm60°F16°C5 mph9 km/h NorthwestClear
July 16
12am62°F17°C5 mph8 km/h NorthwestClear
1am63°F17°C4 mph7 km/h WestClear
2am62°F17°C3 mph6 km/h WestClear
3am59°F15°C3 mph5 km/h WestClear
4am56°F13°C3 mph4 km/h NorthwestClear
5am53°F11°C2 mph4 km/h WestClear
6am50°F10°C3 mph5 km/h WestClear
7am49°F9°C4 mph7 km/h WestClear
8am47°F8°C4 mph7 km/h WestClear
DateLowHighWindDayNight
July 1538°F3°C63°F17°C4 mph6 km/h from NorthwestClearMostly Clear
July 1638°F3°C63°F17°C3 mph5 km/h from NorthwestMostly CloudyMostly Clear
July 1742°F5°C60°F15°C7 mph12 km/h from SouthDrizzleMostly Clear
July 1843°F6°C64°F18°C3 mph5 km/h from WestClearClear
July 1939°F4°C63°F17°C5 mph8 km/h from SouthwestPartly CloudyPartly Cloudy
July 2046°F8°C64°F18°C4 mph6 km/h from EastPartly CloudyPartly Cloudy
July 2147°F8°C65°F18°C6 mph9 km/h from NorthCloudyMostly Cloudy

Yes

Low of 37°F3°C, High of 64°F18°C
Wind: 3 mph5 km/h
Precipitation: None

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