Will I need a jacket?

Here is whether you need a jacket, from the wind chill and how hard you plan to run.

Your details

Jacket check for 8 degrees

No jacket

long sleeves

Feels like5 degrees with 20 km/h wind
Dress as if it is11 degrees (you warm up by about 6)

You should feel a little cold for the first 5 minutes. Feels like uses the wind chill formula the Met Office uses. Wear something bright or reflective in the dark.

The working

8 degrees, 20 km/h wind, dry, an easy run

The wind chill makes 8 degrees feel like 5. You warm up by about 6 degrees on an easy run, so dress as if it is 11: no jacket, long sleeves.

Dress for

A rough guide

Dress as if	Wear
Under 0	Thermal layer, jacket, hat and gloves
0 to 8	Long sleeves, light jacket, gloves
8 to 14	Long sleeves
14 to 20	T shirt
Over 20	Vest or T shirt and shorts

In the dark and wet

Stay safe

Bright or reflective kit in the dark
A light waterproof for proper rain
Take care on wet leaves and ice

Read with care

What this cannot tell you

See the forecastCheck the Met Office.
Know youSome people run warm.
Allow for sunBright sun feels several degrees warmer.

Questions

Common questions

What should I wear running at 10 degrees?

Long sleeves or a T shirt for most people; you warm up fast.

What is wind chill?

How cold it feels on skin with the wind, from the JAG/TI formula.

How much do you warm up running?

Roughly 6 to 11 degrees, depending on effort.

Is it safe to run in the cold?

Yes for most people with layers; see a GP if cold air brings on chest pain or wheeze.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Stop and get help

Stop and get help if you have chest pain, feel faint or are unusually breathless, and call 999 if chest pain does not go away. Check with your GP before stepping up if you have a heart, lung or joint condition.