Yes

you do need a jacket based on the weather in New Tecumseth (Alliston), Ontario, Canada 1 second ago

Why? Because it's not very warm out!
52°F11°C & Cloudy

Wind is 7 mph11 km/h from the NW, gusting to 14 mph23 km/h
October 7
1am51°F11°C7 mph11 km/h NWMostly Clear
2am50°F10°C7 mph10 km/h WMostly Clear
3am49°F10°C6 mph10 km/h WPartly Cloudy
4am49°F9°C7 mph11 km/h WPartly Cloudy
5am49°F9°C8 mph13 km/h WPartly Cloudy
6am48°F9°C8 mph13 km/h WMostly Cloudy
7am49°F10°C9 mph14 km/h WMostly Cloudy
8am50°F10°C9 mph14 km/h WMostly Cloudy
9am51°F11°C11 mph17 km/h NWPartly Cloudy
10am53°F12°C13 mph21 km/h NWPartly Cloudy
11am55°F13°C14 mph23 km/h NWPartly Cloudy
12pm56°F14°C14 mph22 km/h NWPartly Cloudy
DateLowHighWindDayNight
October 746°F8°C60°F16°C12 mph19 km/h from NWPartly CloudyMostly Clear
October 842°F6°C56°F13°C8 mph13 km/h from NWPartly CloudyPartly Cloudy
October 941°F5°C53°F12°C11 mph17 km/h from NWDrizzlePartly Cloudy
October 1036°F2°C56°F13°C7 mph11 km/h from NWPartly CloudyMostly Clear
October 1140°F4°C69°F20°C9 mph15 km/h from SWPartly CloudyMostly Cloudy
October 1243°F6°C59°F15°C12 mph19 km/h from NWPartly CloudyPartly Cloudy
October 1338°F4°C57°F14°C5 mph7 km/h from NEMostly CloudyDrizzle

Yes

Low of 42°F6°C, High of 55°F13°C
Wind: 8 mph13 km/h
Precipitation: 14% rain

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