Yes

you do need a jacket based on the weather in Galway, Ireland 1 second ago

Why? Because it's cool. Pleasantly cool, but cool!
57°F14°C & Cloudy

Wind is 9 mph15 km/h from the Southwest, gusting to 17 mph28 km/h
September 19
2am57°F14°C9 mph15 km/h SouthwestCloudy
3am57°F14°C8 mph13 km/h SouthwestCloudy
4am57°F14°C9 mph14 km/h SouthwestCloudy
5am58°F15°C9 mph14 km/h SouthwestCloudy
6am59°F15°C9 mph14 km/h SouthwestCloudy
7am59°F15°C10 mph15 km/h SouthwestCloudy
8am60°F16°C10 mph15 km/h SouthwestCloudy
9am60°F16°C10 mph16 km/h SouthwestCloudy
10am60°F16°C10 mph16 km/h WestCloudy
11am60°F16°C10 mph16 km/h WestCloudy
12pm60°F15°C10 mph16 km/h WestCloudy
1pm59°F15°C8 mph14 km/h WestCloudy
DateLowHighWindDayNight
September 1853°F12°C60°F16°C9 mph15 km/h from SouthwestCloudyMostly Cloudy
September 1948°F9°C58°F15°C10 mph17 km/h from NorthRainMostly Clear
September 2044°F7°C56°F13°C15 mph24 km/h from NorthMostly ClearMostly Clear
September 2141°F5°C57°F14°C4 mph7 km/h from NortheastPartly CloudyPartly Cloudy
September 2243°F6°C58°F15°C6 mph9 km/h from SoutheastMostly ClearPartly Cloudy
September 2346°F8°C60°F16°C10 mph16 km/h from SoutheastMostly CloudyMostly Cloudy
September 2448°F9°C61°F16°C12 mph19 km/h from SoutheastMostly CloudyMostly Cloudy

Yes

Low of 47°F9°C, High of 58°F15°C
Wind: 10 mph17 km/h
Precipitation: 60% rain

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