No
you don't need a jacket based on the weather in Lake Forest, CA, USA 1 second ago
76°F24°C & Mostly Clear
Wind is 4 mph6 km/h from the West, gusting to 6 mph10 km/h
| September 18 | ||||
| 11pm | 74°F23°C | 3 mph5 km/h West | Mostly Clear | |
| September 19 | ||||
| 12am | 73°F23°C | 2 mph3 km/h West | Mostly Clear | |
| 1am | 72°F22°C | 2 mph2 km/h South | Mostly Clear | |
| 2am | 71°F22°C | 2 mph3 km/h South | Mostly Clear | |
| 3am | 72°F22°C | 1 mph2 km/h West | Partly Cloudy | |
| 4am | 72°F22°C | 2 mph3 km/h West | Partly Cloudy | |
| 5am | 69°F21°C | 2 mph3 km/h Southwest | Mostly Clear | |
| 6am | 69°F20°C | 2 mph3 km/h Southwest | Mostly Clear | |
| 7am | 68°F20°C | 1 mph2 km/h Southwest | Partly Cloudy | |
| 8am | 67°F20°C | 1 mph2 km/h Southwest | Partly Cloudy | |
| 9am | 67°F19°C | 1 mph2 km/h Southwest | Partly Cloudy | |
| 10am | 67°F19°C | 1 mph2 km/h Southeast | Mostly Cloudy | |
| Date | Low | High | Wind | Day | Night |
|---|---|---|---|---|---|
| September 18 | 68°F20°C | 84°F29°C | 4 mph6 km/h from South | Partly Cloudy | Mostly Clear |
| September 19 | 67°F19°C | 81°F27°C | 5 mph8 km/h from Southwest | Mostly Clear | Clear |
| September 20 | 64°F18°C | 84°F29°C | 5 mph8 km/h from West | Clear | Mostly Clear |
| September 21 | 63°F17°C | 82°F28°C | 5 mph7 km/h from Southwest | Partly Cloudy | Mostly Cloudy |
| September 22 | 68°F20°C | 87°F31°C | 5 mph7 km/h from West | Mostly Clear | Mostly Clear |
| September 23 | 68°F20°C | 89°F32°C | 5 mph7 km/h from Southwest | Mostly Clear | Mostly Clear |
| September 24 | 67°F19°C | 87°F30°C | 5 mph7 km/h from West | Clear | Clear |
No
Low of 67°F20°C, High of 82°F28°CWind: 5 mph8 km/h
Precipitation: None