Yes

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

Why? Because it's cool. Pleasantly cool, but cool!
54°F12°C & Mostly Clear

Wind is 8 mph13 km/h from the Northeast, gusting to 19 mph30 km/h
May 4
2pm53°F12°C7 mph11 km/h NortheastPartly Cloudy
3pm51°F10°C6 mph10 km/h NortheastMostly Cloudy
4pm50°F10°C7 mph11 km/h NorthPartly Cloudy
5pm48°F9°C7 mph11 km/h NorthMostly Clear
6pm47°F8°C7 mph11 km/h NorthPartly Cloudy
7pm46°F8°C7 mph11 km/h NorthMostly Cloudy
8pm46°F8°C8 mph12 km/h NorthMostly Cloudy
9pm45°F7°C7 mph12 km/h NorthMostly Cloudy
10pm44°F7°C7 mph12 km/h NortheastMostly Cloudy
11pm44°F7°C7 mph12 km/h NortheastPartly Cloudy
May 5
12am43°F6°C7 mph12 km/h NortheastMostly Clear
1am43°F6°C7 mph12 km/h NortheastMostly Clear
DateLowHighWindDayNight
May 347°F8°C57°F14°C7 mph12 km/h from NortheastPartly CloudyPartly Cloudy
May 443°F6°C58°F14°C10 mph16 km/h from NortheastPartly CloudyMostly Cloudy
May 543°F6°C58°F15°C10 mph16 km/h from NortheastPartly CloudyPartly Cloudy
May 644°F7°C58°F14°C8 mph14 km/h from NortheastMostly CloudyMostly Cloudy
May 746°F8°C59°F15°C9 mph14 km/h from NortheastMostly CloudyPartly Cloudy
May 845°F7°C60°F16°C10 mph16 km/h from NortheastMostly ClearMostly Clear
May 945°F7°C65°F18°C8 mph13 km/h from EastClearMostly Clear

Yes

Low of 44°F7°C, High of 57°F14°C
Wind: 10 mph16 km/h
Precipitation: None

Support This Page