Yes

you do need a jacket based on the weather in Dial Post, Horsham RH13, UK 1 second ago

Why? Because it's raining in your area!
59°F15°C & Rain

Wind is 8 mph13 km/h from the South, gusting to 14 mph22 km/h
August 31
7pm59°F15°C8 mph13 km/h SouthwestMostly Clear
8pm59°F15°C9 mph15 km/h SouthwestPartly Cloudy
9pm59°F15°C10 mph16 km/h SouthwestPartly Cloudy
10pm59°F15°C10 mph16 km/h SouthwestMostly Clear
11pm59°F15°C11 mph17 km/h SouthwestMostly Clear
September 1
12am59°F15°C12 mph19 km/h SouthwestMostly Clear
1am58°F15°C12 mph19 km/h SouthwestMostly Clear
2am59°F15°C13 mph22 km/h SouthwestMostly Cloudy
3am60°F15°C14 mph23 km/h SouthwestMostly Cloudy
4am61°F16°C15 mph24 km/h SouthwestMostly Cloudy
5am62°F17°C17 mph27 km/h SouthwestWindy
6am63°F17°C18 mph29 km/h SouthwestWindy
DateLowHighWindDayNight
August 3054°F12°C69°F20°C8 mph13 km/h from SouthwestPartly CloudyDrizzle
August 3158°F14°C67°F19°C16 mph26 km/h from SouthwestDrizzleDrizzle
September 155°F13°C66°F19°C13 mph21 km/h from SouthRainDrizzle
September 259°F15°C68°F20°C23 mph36 km/h from SouthwestRainRain
September 357°F14°C65°F18°C16 mph26 km/h from SouthwestRainMostly Clear
September 452°F11°C67°F20°C11 mph17 km/h from SouthwestPartly CloudyMostly Cloudy
September 554°F12°C68°F20°C10 mph17 km/h from SoutheastMostly CloudyMostly Cloudy

Yes

Low of 58°F15°C, High of 66°F19°C
Wind: 16 mph26 km/h
Precipitation: 59% rain

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