No
you don't need a jacket based on the weather in Castro Valley, CA, USA 1 second ago
77°F25°C & Clear
Wind is 9 mph15 km/h from the West, gusting to 12 mph20 km/h
| May 19 | ||||
| 5pm | 78°F25°C | 10 mph16 km/h West | Clear | |
| 6pm | 78°F26°C | 10 mph17 km/h West | Clear | |
| 7pm | 77°F25°C | 11 mph17 km/h West | Clear | |
| 8pm | 76°F24°C | 10 mph16 km/h West | Clear | |
| 9pm | 74°F23°C | 9 mph14 km/h West | Clear | |
| 10pm | 70°F21°C | 8 mph12 km/h West | Clear | |
| 11pm | 66°F19°C | 6 mph10 km/h Southwest | Clear | |
| May 20 | ||||
| 12am | 62°F17°C | 6 mph10 km/h Southwest | Clear | |
| 1am | 59°F15°C | 6 mph9 km/h Southwest | Clear | |
| 2am | 56°F14°C | 5 mph9 km/h Southwest | Clear | |
| 3am | 55°F13°C | 5 mph8 km/h Southwest | Mostly Clear | |
| 4am | 53°F12°C | 5 mph7 km/h Southwest | Mostly Clear | |
| Date | Low | High | Wind | Day | Night |
|---|---|---|---|---|---|
| May 19 | 52°F11°C | 78°F26°C | 7 mph11 km/h from West | Clear | Mostly Clear |
| May 20 | 51°F10°C | 74°F23°C | 6 mph10 km/h from Southwest | Clear | Clear |
| May 21 | 49°F9°C | 78°F25°C | 6 mph10 km/h from West | Clear | Clear |
| May 22 | 50°F10°C | 70°F21°C | 9 mph14 km/h from Southwest | Clear | Partly Cloudy |
| May 23 | 49°F10°C | 64°F18°C | 10 mph16 km/h from Southwest | Mostly Clear | Partly Cloudy |
| May 24 | 49°F10°C | 69°F21°C | 6 mph10 km/h from West | Mostly Clear | Mostly Clear |
| May 25 | 50°F10°C | 65°F18°C | 9 mph14 km/h from Southwest | Mostly Clear | Mostly Cloudy |
Yes
Low of 51°F11°C, High of 73°F23°CWind: 6 mph10 km/h
Precipitation: None