Yes

you do need a jacket based on the weather in Kalgoorlie - Boulder WA, Australia 1 second ago

Why? Because it's pretty chilly!
51°F11°C & Clear

Wind is 6 mph10 km/h from the Southwest, gusting to 9 mph15 km/h
September 18
12pm50°F10°C6 mph10 km/h SouthwestClear
1pm49°F9°C6 mph10 km/h SouthwestClear
2pm48°F9°C6 mph10 km/h SouthwestClear
3pm46°F8°C7 mph11 km/h SouthwestClear
4pm45°F7°C7 mph11 km/h SouthwestClear
5pm44°F7°C7 mph11 km/h SouthwestClear
6pm44°F7°C6 mph10 km/h SouthwestClear
7pm47°F9°C7 mph11 km/h SouthwestClear
8pm54°F12°C8 mph13 km/h SouthwestClear
9pm59°F15°C9 mph14 km/h SouthwestClear
10pm62°F17°C9 mph14 km/h SouthwestClear
11pm66°F19°C8 mph13 km/h SouthwestMostly Clear
DateLowHighWindDayNight
September 1748°F9°C71°F22°C11 mph17 km/h from SouthwestClearClear
September 1844°F7°C71°F22°C9 mph14 km/h from SouthwestMostly ClearMostly Clear
September 1946°F8°C72°F22°C6 mph9 km/h from SoutheastMostly ClearClear
September 2048°F9°C75°F24°C9 mph14 km/h from SoutheastClearClear
September 2147°F8°C74°F23°C10 mph17 km/h from EastClearClear
September 2247°F8°C76°F24°C10 mph16 km/h from EastClearClear
September 2350°F10°C81°F27°C6 mph10 km/h from NorthClearClear

Yes

Low of 44°F7°C, High of 71°F22°C
Wind: 9 mph14 km/h
Precipitation: None

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