Yes

you do need a jacket based on the weather in Siwan, Bihar, India 1 second ago

Why? Because the rain is just enough to ruin your hairstyle but not your mood!
86°F30°C & Rain

Wind is 5 mph8 km/h from the East, gusting to 9 mph14 km/h
September 15
3am86°F30°C5 mph8 km/h EastRain
4am86°F30°C5 mph8 km/h EastRain
5am86°F30°C5 mph7 km/h EastDrizzle
6am85°F30°C5 mph8 km/h EastDrizzle
7am84°F29°C5 mph7 km/h EastCloudy
8am83°F28°C5 mph7 km/h EastCloudy
9am82°F28°C4 mph7 km/h EastCloudy
10am81°F27°C5 mph8 km/h EastMostly Cloudy
11am81°F27°C5 mph8 km/h EastMostly Cloudy
12pm80°F27°C5 mph8 km/h EastMostly Cloudy
1pm80°F26°C5 mph8 km/h EastDrizzle
2pm79°F26°C5 mph8 km/h EastDrizzle
DateLowHighWindDayNight
September 1478°F26°C86°F30°C5 mph8 km/h from EastRainRain
September 1577°F25°C84°F29°C6 mph10 km/h from EastRainRain
September 1677°F25°C85°F29°C7 mph11 km/h from EastRainRain
September 1777°F25°C85°F30°C6 mph9 km/h from EastRainRain
September 1877°F25°C86°F30°C3 mph5 km/h from EastThunderstormsThunderstorms
September 1977°F25°C89°F31°C5 mph8 km/h from EastRainThunderstorms
September 2077°F25°C89°F32°C4 mph7 km/h from EastThunderstormsThunderstorms

No

Low of 77°F25°C, High of 84°F29°C
Wind: 6 mph10 km/h
Precipitation: 80% rain

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