Yes

you do need a jacket based on the weather in Montreal, QC, Canada 2 minutes ago

Why? Because it's quite chilly!
46°F8°C & Cloudy

Wind is 8 mph13 km/h from the Northeast, gusting to 17 mph27 km/h
May 9
12am46°F8°C8 mph13 km/h NortheastCloudy
1am45°F7°C9 mph15 km/h NortheastCloudy
2am44°F7°C9 mph15 km/h NortheastCloudy
3am43°F6°C9 mph15 km/h NortheastCloudy
4am43°F6°C9 mph15 km/h NortheastCloudy
5am43°F6°C10 mph16 km/h NortheastCloudy
6am42°F6°C10 mph16 km/h NortheastCloudy
7am43°F6°C11 mph18 km/h NortheastCloudy
8am43°F6°C11 mph18 km/h NortheastCloudy
9am43°F6°C11 mph18 km/h NortheastDrizzle
10am44°F7°C11 mph17 km/h NortheastDrizzle
11am46°F8°C10 mph17 km/h NortheastDrizzle
DateLowHighWindDayNight
May 844°F7°C51°F11°C6 mph9 km/h from NorthCloudyDrizzle
May 942°F6°C51°F10°C10 mph17 km/h from NortheastRainRain
May 1048°F9°C62°F16°C7 mph11 km/h from NorthwestDrizzlePartly Cloudy
May 1140°F5°C63°F17°C8 mph13 km/h from NorthwestClearPartly Cloudy
May 1249°F9°C72°F22°C8 mph13 km/h from WestPartly CloudyMostly Clear
May 1351°F11°C76°F25°C8 mph13 km/h from EastPartly CloudyMostly Cloudy
May 1457°F14°C79°F26°C7 mph12 km/h from SouthwestPartly CloudyMostly Cloudy

Yes

Low of 42°F6°C, High of 51°F11°C
Wind: 10 mph17 km/h
Precipitation: 89% rain

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