Yes

you do need a jacket based on the weather in Phoenix, AZ, USA 1 second ago

Why? Because it's cool. Pleasantly cool, but cool!
51°F10°C & Mostly Clear

Wind is 2 mph3 km/h from the North, gusting to 4 mph6 km/h
April 19
7am51°F10°C2 mph3 km/h NorthClear
8am51°F10°C2 mph4 km/h NortheastMostly Clear
9am50°F10°C2 mph3 km/h NortheastClear
10am52°F11°C1 mph2 km/h NortheastClear
11am55°F13°C2 mph3 km/h EastMostly Clear
12pm58°F15°C1 mph2 km/h NortheastClear
1pm62°F17°C1 mph2 km/h NorthClear
2pm65°F18°C2 mph3 km/h NorthwestClear
3pm68°F20°C3 mph4 km/h NorthwestMostly Clear
4pm70°F21°C3 mph6 km/h NorthwestClear
5pm72°F22°C5 mph7 km/h NorthwestClear
6pm73°F23°C5 mph7 km/h WestClear
DateLowHighWindDayNight
April 1950°F10°C74°F23°C3 mph6 km/h from WestClearClear
April 2054°F12°C83°F29°C3 mph5 km/h from WestClearPartly Cloudy
April 2159°F15°C88°F31°C3 mph5 km/h from WestMostly CloudyClear
April 2262°F17°C90°F32°C4 mph6 km/h from WestClearClear
April 2366°F19°C89°F32°C4 mph6 km/h from WestClearClear
April 2467°F19°C89°F32°C4 mph6 km/h from SouthwestMostly ClearPartly Cloudy
April 2568°F20°C91°F33°C4 mph6 km/h from SouthwestMostly ClearClear

Yes

Low of 55°F13°C, High of 83°F29°C
Wind: 3 mph5 km/h
Precipitation: None

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