Yes
you do need a jacket based on the weather in Chelmsford, MA, USA 1 second ago
Why? Because Jack Frost is nipping at your nose!
25°F-4°C & Mostly Cloudy
Wind is 4 mph7 km/h from the Northwest, gusting to 11 mph18 km/h
| December 4 | ||||
| 4am | 25°F-4°C | 5 mph8 km/h Northwest | Mostly Clear | |
| 5am | 24°F-5°C | 5 mph7 km/h Northwest | Clear | |
| 6am | 23°F-5°C | 4 mph7 km/h West | Clear | |
| 7am | 23°F-5°C | 4 mph6 km/h West | Clear | |
| 8am | 24°F-5°C | 3 mph6 km/h West | Clear | |
| 9am | 27°F-3°C | 3 mph5 km/h West | Clear | |
| 10am | 30°F-1°C | 4 mph6 km/h Southwest | Clear | |
| 11am | 33°F0°C | 4 mph7 km/h Southwest | Clear | |
| 12pm | 35°F2°C | 5 mph9 km/h Southwest | Mostly Clear | |
| 1pm | 36°F2°C | 7 mph11 km/h South | Partly Cloudy | |
| 2pm | 37°F3°C | 7 mph12 km/h South | Mostly Cloudy | |
| 3pm | 36°F2°C | 8 mph12 km/h South | Cloudy | |
| Date | Low | High | Wind | Day | Night |
|---|---|---|---|---|---|
| December 4 | 23°F-5°C | 37°F3°C | 6 mph9 km/h from South | Partly Cloudy | Rain |
| December 5 | 30°F-1°C | 39°F4°C | 10 mph15 km/h from West | Drizzle | Mostly Clear |
| December 6 | 21°F-6°C | 30°F-1°C | 11 mph18 km/h from West | Mostly Clear | Mostly Clear |
| December 7 | 18°F-8°C | 32°F0°C | 8 mph12 km/h from West | Mostly Clear | Mostly Cloudy |
| December 8 | 25°F-4°C | 41°F5°C | 7 mph11 km/h from Southwest | Mostly Cloudy | Partly Cloudy |
| December 9 | 34°F1°C | 49°F10°C | 6 mph10 km/h from Southwest | Partly Cloudy | Drizzle |
| December 10 | 39°F4°C | 54°F12°C | 5 mph8 km/h from Southwest | Drizzle | Cloudy |
Yes
Low of 30°F-1°C, High of 39°F4°CWind: 10 mph15 km/h
Precipitation: 79% rain