Yes

you do need a jacket based on the weather in Friedrichshafen, Germany 1 second ago

Why? Because it's cold. simple as that.
45°F7°C & Partly Cloudy

Wind is 7 mph12 km/h from the SW, gusting to 16 mph25 km/h
April 25
7am46°F8°C8 mph13 km/h WPartly Cloudy
8am47°F9°C9 mph15 km/h WPartly Cloudy
9am49°F9°C9 mph14 km/h WMostly Cloudy
10am49°F10°C8 mph14 km/h WPartly Cloudy
11am50°F10°C8 mph13 km/h WPartly Cloudy
12pm50°F10°C7 mph11 km/h WPartly Cloudy
1pm49°F9°C5 mph7 km/h WPartly Cloudy
2pm47°F8°C3 mph6 km/h WMostly Clear
3pm43°F6°C3 mph5 km/h SWClear
4pm41°F5°C3 mph4 km/h SEClear
5pm40°F4°C3 mph4 km/h SEClear
6pm38°F4°C3 mph4 km/h SEMostly Clear
DateLowHighWindDayNight
April 2436°F2°C50°F10°C8 mph13 km/h from WMostly CloudyMostly Clear
April 2534°F1°C58°F14°C2 mph4 km/h from SWMostly CloudyPartly Cloudy
April 2638°F3°C66°F19°C5 mph8 km/h from SEMostly ClearPartly Cloudy
April 2746°F8°C66°F19°C3 mph4 km/h from WMostly CloudyMostly Cloudy
April 2848°F9°C70°F21°C3 mph5 km/h from NEPartly CloudyPartly Cloudy
April 2949°F10°C74°F23°C4 mph6 km/h from EPartly CloudyMostly Cloudy
April 3051°F11°C70°F21°C3 mph5 km/h from EMostly CloudyRain

Yes

Low of 34°F1°C, High of 58°F15°C
Wind: 2 mph4 km/h
Precipitation: 13% rain

Support This Page