Yes

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

Why? Because just cool enough for a jacket, but not warm enough to ditch it!
52°F11°C & Clear

Wind is 4 mph7 km/h from the North, gusting to 6 mph10 km/h
October 28
11am52°F11°C5 mph8 km/h NorthClear
12pm52°F11°C4 mph6 km/h NorthClear
1pm52°F11°C3 mph5 km/h NorthClear
2pm51°F11°C3 mph4 km/h NorthClear
3pm52°F11°C2 mph3 km/h SoutheastClear
4pm55°F13°C2 mph4 km/h EastClear
5pm59°F15°C3 mph5 km/h EastClear
6pm63°F17°C3 mph5 km/h EastClear
7pm66°F19°C3 mph5 km/h NortheastClear
8pm69°F20°C4 mph7 km/h NorthClear
9pm70°F21°C5 mph9 km/h NorthClear
10pm72°F22°C6 mph9 km/h NorthwestClear
DateLowHighWindDayNight
October 2851°F11°C72°F22°C4 mph7 km/h from NorthClearClear
October 2954°F12°C73°F23°C4 mph7 km/h from NorthwestClearMostly Clear
October 3055°F13°C63°F17°C7 mph11 km/h from WestMostly CloudyPartly Cloudy
October 3153°F12°C66°F19°C4 mph6 km/h from WestMostly ClearMostly Clear
November 153°F12°C68°F20°C4 mph6 km/h from WestMostly ClearPartly Cloudy
November 255°F13°C72°F22°C4 mph6 km/h from WestMostly ClearPartly Cloudy
November 355°F13°C66°F19°C5 mph9 km/h from WestPartly CloudyMostly Cloudy

Yes

Low of 55°F13°C, High of 73°F23°C
Wind: 4 mph7 km/h
Precipitation: None

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