Yes

you do need a jacket based on the weather in Harrowsmith, ON K0H 1V0, Canada 1 second ago

Why? Because it's drizzling and just cool enough for a jacket, but not warm enough to ditch it and it's so windy, your hat will probably launch into orbit!
54°F12°C & Drizzle

Wind is 12 mph20 km/h from the Northwest, gusting to 27 mph44 km/h
October 20
7pm53°F12°C13 mph21 km/h NorthwestDrizzle
8pm53°F12°C12 mph20 km/h NorthwestDrizzle
9pm53°F12°C12 mph19 km/h NorthwestCloudy
10pm53°F12°C11 mph18 km/h NorthwestCloudy
11pm52°F11°C11 mph17 km/h NorthwestMostly Cloudy
October 21
12am51°F11°C11 mph17 km/h NorthwestMostly Cloudy
1am51°F11°C10 mph16 km/h NorthwestPartly Cloudy
2am50°F10°C10 mph16 km/h WestMostly Clear
3am49°F9°C10 mph15 km/h WestMostly Clear
4am48°F9°C9 mph15 km/h WestClear
5am47°F8°C9 mph14 km/h WestClear
6am46°F8°C8 mph13 km/h WestClear
DateLowHighWindDayNight
October 2048°F9°C58°F15°C10 mph16 km/h from NorthwestRainMostly Clear
October 2142°F5°C57°F14°C7 mph12 km/h from SouthPartly CloudyDrizzle
October 2244°F7°C53°F12°C8 mph14 km/h from SouthwestRainRain
October 2341°F5°C51°F11°C9 mph14 km/h from WestDrizzleMostly Cloudy
October 2437°F3°C49°F10°C7 mph11 km/h from WestMostly CloudyPartly Cloudy
October 2535°F2°C51°F11°C3 mph5 km/h from NorthwestMostly CloudyMostly Cloudy
October 2637°F3°C52°F11°C5 mph9 km/h from EastDrizzlePartly Cloudy

Yes

Low of 42°F6°C, High of 57°F14°C
Wind: 7 mph12 km/h
Precipitation: None

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