Yes

you do need a jacket based on the weather in Rockville, MD 20851, USA 1 second ago

Why? Because it's not very warm out!
57°F14°C & Mostly Cloudy

Wind is 4 mph7 km/h from the North, gusting to 11 mph18 km/h
May 29
1am57°F14°C5 mph7 km/h NorthMostly Cloudy
2am56°F13°C4 mph7 km/h NorthwestCloudy
3am56°F13°C5 mph7 km/h NorthwestCloudy
4am55°F13°C4 mph6 km/h NorthwestCloudy
5am55°F13°C3 mph5 km/h NorthwestCloudy
6am55°F13°C3 mph6 km/h NorthwestCloudy
7am56°F13°C3 mph5 km/h NorthwestCloudy
8am58°F14°C3 mph5 km/h NorthwestCloudy
9am60°F16°C3 mph5 km/h NorthwestCloudy
10am63°F17°C3 mph5 km/h WestCloudy
11am66°F19°C4 mph6 km/h WestCloudy
12pm69°F20°C4 mph7 km/h WestCloudy
DateLowHighWindDayNight
May 2955°F13°C75°F24°C4 mph7 km/h from WestMostly CloudyRain
May 3058°F14°C76°F25°C4 mph6 km/h from WestRainRain
May 3154°F12°C67°F19°C10 mph16 km/h from WestRainMostly Clear
June 149°F10°C70°F21°C9 mph15 km/h from WestPartly CloudyPartly Cloudy
June 253°F12°C75°F24°C4 mph7 km/h from WestPartly CloudyClear
June 354°F12°C79°F26°C4 mph7 km/h from NorthwestMostly ClearMostly Clear
June 460°F16°C82°F28°C3 mph6 km/h from WestMostly ClearPartly Cloudy

Yes

Low of 58°F15°C, High of 76°F25°C
Wind: 4 mph6 km/h
Precipitation: 56% rain

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