What Temperature Is Flannel Weather? A Guide to Wearing a Flannel Shirt

Flannel weather starts at around 20°C and runs all the way down to a hard frost. The shirt stays the same. What changes is what goes over it. This is a plain guide to wearing a flannel shirt through the British year, band by band, with the layer to add as the thermometer drops.

The short answer

A flannel shirt on its own suits roughly 14°C to 20°C. Below 14°C, add a gilet. Below 8°C, add a jacket. Below 3°C, wear all three. Above 20°C, a tee does the job and the flannel waits for the evening.

These are rules of thumb, not lab figures. Two things move them more than anything else.

• Moving or standing still. Walking uphill, dress one band warmer than the thermometer says. Standing on a touchline, a riverbank or a station platform, dress one band colder.
• Wind. On exposed ground, the coast or the open hill, wind takes warmth faster than the number suggests. Treat a windy 12°C as a still 8°C.

Above 20°C: tee first, flannel for the evening

On a warm day the flannel comes off and the tee does the work. The Logo Tee in Forest or Sea Fog is 100% cotton, light enough alone and thin enough to sit under a shirt later, £35. Keep the flannel in the car or over the back of a chair. When the sun drops, it goes back on, open over the tee with the sleeves rolled.

14°C to 20°C: the flannel on its own

This is flannel weather in its plainest form. One shirt over a tee, buttoned or open, sleeves down in the morning and rolled by lunch.

The Brae Flannel Shirt is 100% cotton flannel, brushed on both sides, medium weight and a regular fit cut to layer. The hidden button-down collar keeps the points still in the wind, which matters more than it sounds once there is no jacket over the top. It comes in Marine, Offshore, Raven and Rifle, £95.

The Munro Flannel Shirt is the plain version: brushed cotton in solid field colours, two deep pleated chest pockets under buttoned flaps, and contrast drill cotton where shirts wear first. Same regular fit, same collar, in Rifle Green and Seastorm, £95.

8°C to 14°C: flannel and a gilet

The first properly cold mornings. The flannel alone is fine once you are moving, and cold at the gate before you start. A gilet fixes that and leaves the arms free.

The Torr Wool Gilet is cut to go over a flannel and under a jacket. It is made from our own Tech Wool, 60% wool with synthetics blended in for strength and shape, with a contrast brushed cotton inner neck so nothing sits cold against the skin. In Peat and Heather Green, £185. If the sun comes out, it comes off and goes in the bag.

3°C to 8°C: flannel under a jacket

Now the flannel becomes the mid layer. A wool jacket over it covers the cold commute, the coast path and the walk to the station.

The Arkle Wool Jacket was cut to sit well over a flannel or a jumper, somewhere between a jacket and an overshirt. It is the same Tech Wool as the Torr, with two pleated chest patch pockets, two zipped waist pockets and a brushed cotton inner neck, £240. For more on the choice between the two, read Gilet or Jacket? Choosing Between the Torr and the Arkle.

Below 3°C: all three

Frost, a still morning on the river, a long wait at the side of a pitch. Flannel, gilet, jacket. The gilet keeps the core warm, the jacket keeps the arms warm, and the flannel does the quiet work underneath. Add a hat and gloves of your choice and stay out.

And when it rains

Temperature decides the layers. Rain decides the outer. A flannel shirt is cotton and none of the layers above are sold as waterproof. On the wettest days, whatever the band, put your own waterproof shell over the top. The rest of the time, the flannel and the wool do the job.

Common questions

What temperature is flannel weather?

Roughly 14°C to 20°C for a flannel shirt worn on its own. Below that the flannel stays on and a gilet or jacket goes over it. Above 20°C most people swap it for a tee.

Is a flannel shirt warm enough for winter?

On its own, rarely. As a mid layer, yes. Under a wool gilet and a jacket, a flannel is a warm and comfortable part of a winter kit.

Can you wear a flannel shirt in summer?

On cool evenings, early mornings and wet days, yes. Wear it open over a tee with the sleeves rolled, and take it off when the day warms up.

What do you wear over a flannel shirt?

A wool gilet when the arms need to stay free, a wool jacket when it gets colder, and your own waterproof shell when it rains.

One shirt, four bands

The flannel stays in the kit all year. Only the layers around it change. Shop the Brae and Munro flannel shirts, and take 20% off two or more flannel shirts. For how to pick one in the first place, read How to Choose a Flannel Shirt, and for the fabric behind the gilet and jacket, What Is Tech Wool?

Bought once. Worn often.