Yes

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

Why? Because it's quite chilly.
47°F8°C & Cloudy

Wind is 12 mph19 km/h from the NE, gusting to 24 mph39 km/h
April 26
8pm46°F8°C11 mph18 km/h NEPartly Cloudy
9pm45°F7°C10 mph16 km/h NEPartly Cloudy
10pm45°F7°C8 mph14 km/h NEMostly Cloudy
11pm44°F7°C7 mph11 km/h NECloudy
April 27
12am43°F6°C5 mph8 km/h NECloudy
1am43°F6°C4 mph6 km/h NECloudy
2am42°F6°C3 mph5 km/h ECloudy
3am43°F6°C4 mph7 km/h ECloudy
4am45°F7°C4 mph7 km/h SECloudy
5am46°F8°C5 mph8 km/h SECloudy
6am47°F8°C5 mph8 km/h SECloudy
7am48°F9°C6 mph10 km/h SEDrizzle
DateLowHighWindDayNight
April 2633°F1°C51°F11°C10 mph15 km/h from NEClearDrizzle
April 2742°F6°C63°F17°C12 mph19 km/h from SRainMostly Cloudy
April 2858°F14°C73°F23°C11 mph17 km/h from SWDrizzleDrizzle
April 2950°F10°C60°F15°C8 mph13 km/h from NERainRain
April 3052°F11°C70°F21°C6 mph10 km/h from WRainPartly Cloudy
May 148°F9°C71°F22°C5 mph8 km/h from SWPartly CloudyMostly Cloudy
May 253°F12°C68°F20°C5 mph8 km/h from SECloudyCloudy

Yes

Low of 43°F6°C, High of 63°F17°C
Wind: 12 mph19 km/h
Precipitation: 72% rain

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