No

Why? Because you should be inside at home! #StayHome

But if you absolutely had to go out to get groceries, medication or other essential travel, No, you don't need a jacket.

Based on the weather in Barnstaple, UK as of May 25, 2020 4:12pm local time.

Now

Partly Cloudy
Temp: 65°F19°C
Wind: 7 MPH11 KPH
Precipitation: None

Today

Next 2 hours: No

Next 4 hours: No

Next 8 hours: Yes

Tomorrow

Yes

Mostly cloudy throughout the day.
Low of 48°F9°C, High of 64°F18°C
Wind: 5 MPH8 KPH
Precipitation: 7% rain