Yes

you do need a jacket based on the weather in Piedmont, CA, USA 1 second ago

Why? Because it's bitterly cold.
47°F8°C & Cloudy

Wind is 6 mph9 km/h from the SE, gusting to 11 mph18 km/h
March 29
8am47°F8°C6 mph10 km/h SECloudy
9am47°F8°C6 mph10 km/h SECloudy
10am46°F8°C7 mph12 km/h SEDrizzle
11am46°F8°C8 mph13 km/h SERain
12pm47°F8°C9 mph15 km/h SERain
1pm48°F9°C11 mph18 km/h SEDrizzle
2pm49°F9°C13 mph22 km/h SEDrizzle
3pm49°F10°C14 mph23 km/h SEDrizzle
4pm50°F10°C15 mph24 km/h SERain
5pm50°F10°C15 mph24 km/h SERain
6pm50°F10°C16 mph26 km/h SERain
7pm51°F11°C16 mph25 km/h SERain
DateLowHighWindDayNight
March 2946°F8°C52°F11°C13 mph21 km/h from SERainDrizzle
March 3045°F7°C58°F15°C7 mph11 km/h from NERainPartly Cloudy
March 3145°F7°C60°F16°C6 mph9 km/h from SWPartly CloudyMostly Clear
April 147°F8°C68°F20°C4 mph7 km/h from NWClearClear
April 249°F9°C69°F21°C4 mph6 km/h from SWClearPartly Cloudy
April 350°F10°C63°F17°C7 mph11 km/h from SWMostly CloudyMostly Clear
April 445°F7°C55°F13°C9 mph14 km/h from NWMostly ClearPartly Cloudy

Yes

Low of 46°F8°C, High of 58°F15°C
Wind: 7 mph11 km/h
Precipitation: 46% rain

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