Yes

you do need a jacket based on the weather in Graz, Austria 1 second ago

Why? Because you're not freezing, but you’ll definitely start complaining if it lasts much longer!

47°F8°C & Mostly Cloudy

Wind is 2 mph3 km/h from the East, gusting to 6 mph10 km/h

Date	Low	High	Wind	Day	Night
February 24	35°F2°C	50°F10°C	3 mph4 km/h from Southeast	Mostly Cloudy	Cloudy
February 25	38°F3°C	47°F9°C	2 mph3 km/h from Northeast	Rain	Cloudy
February 26	36°F2°C	45°F7°C	2 mph3 km/h from Southwest	Drizzle	Partly Cloudy
February 27	33°F0°C	47°F9°C	2 mph4 km/h from Southwest	Mostly Cloudy	Drizzle
February 28	34°F1°C	45°F7°C	3 mph5 km/h from North	Mostly Cloudy	Mostly Cloudy
March 1	33°F0°C	46°F8°C	5 mph7 km/h from North	Mostly Cloudy	Partly Cloudy
March 2	31°F-1°C	49°F9°C	3 mph5 km/h from Southeast	Partly Cloudy	Mostly Clear

Low of 38°F4°C, High of 47°F9°C
Wind: 2 mph3 km/h
Precipitation: 68% rain