What to Wear for a Half Marathon: Race-Day Outfit by Weather, Chafing Fixes, and a Checklist

Thirteen point one miles is long enough for small clothing problems to become big ones. A seam that is barely noticeable on a 4-mile run can rub the skin raw by mile 10. A jacket that felt right in the corral turns into a sweat-soaked weight tied around your waist. A pair of new socks can hand you a blister before the halfway mat.

The good news is that the right half marathon outfit is simple, and most of it is already in your drawer. This guide covers the one rule that prevents most race-day problems, a temperature chart for choosing layers, what to wear on top, on the bottom, and on your feet, how to handle a cold start, how to prevent chafing, what to carry, and a checklist to pack the night before. If your shoes are near the end of their life, read our guide on how often to replace running shoes first; no outfit fixes worn-out cushioning.

The One Rule: Nothing New on Race Day

Every item you wear on race morning should have already done a long run with you, ideally one of 8 miles or more. That includes shoes, socks, shorts, sports bra, shirt, headband, and anything you plan to carry. Long runs reveal what short runs hide: a waistband that slips when it gets wet, a sleeve seam that rubs the underarm, a sock that bunches under the arch.

This rule catches people out at race expos, where it is tempting to buy a new shirt or a fresh pair of shorts the day before. Buy them if you like, but save them for the week after. The same goes for the free race shirt in your goody bag: it has never been washed, you do not know where its seams sit, and a few thousand other runners will be wearing it too.

Do a dress rehearsal on your last long run, two or three weeks out. Wear the complete outfit at roughly the same time of day as your race start, carry your gels in the pockets you plan to use, and note anything that rubs, slides, or bounces. You still have time to fix it.

Dress for Mile 3, Not the Start Line

Standing in the corral feels colder than running. Within the first mile or two your body heats up, and a long-sleeve top that felt essential at the start becomes too warm. A common rule of thumb is to dress as if it were 15 to 20°F warmer than the start temperature. It is a starting point, not a law: runners who feel the cold, those running at an easy pace, and anyone racing in wind or rain should lean toward the cooler end of that range.

Use the forecast for your start time, not the daily high, and look at wind and humidity as well as temperature.

Start temperature	Top	Bottom	Extras	Worth knowing
70°F and above	Singlet or light technical tee	Shorts	Cap or visor, sunglasses, sunscreen	Heat slows everyone; adjust your goal pace
60–69°F	Short-sleeve technical tee or singlet	Shorts	Cap or headband	The range where most runners overdress
50–59°F	Short-sleeve technical tee	Shorts	Arm sleeves you can push down	Close to ideal racing weather
40–49°F	Short-sleeve tee plus arm sleeves, or a light long sleeve	Shorts or capris	Thin gloves, throwaway layer	Gloves usually come off in the first few miles
30–39°F	Long-sleeve technical top	Tights, or shorts for warm-blooded runners	Gloves, headband or ear cover, throwaway sweatshirt	Stay warm in the corral, then shed
Below 30°F	Long-sleeve base layer plus a light wind layer	Tights	Hat, gloves, throwaway layers	Protect hands and ears; avoid cotton entirely

Rain changes things less than you might think. A light, fitted technical shirt and a cap to keep water out of your eyes beat a rain jacket, which traps heat and stays wet anyway. Wind does change things: a headwind on an exposed course can make 45°F feel like the 30s, so consider arm sleeves and gloves you can remove. For racing in real cold, our winter running gear guide goes deeper on layering.

Tops, Bottoms, and Socks

Tops

Choose a technical fabric such as polyester or nylon blends, or merino wool for cool races, with flat seams under the arms and across the shoulders. Fit matters more than brand: a shirt that is too loose flaps and rubs, and one that is too tight can chafe under the arms.

For warm races, the Under Armour Iso-Chill Run Short Sleeve uses a cooling fabric with flat-knit construction and reflective details, though its slim, men's cut will not suit every body. For mild and cool days, the Under Armour Tech 2.0 Tee is a basic men's technical shirt at $25 with anti-odor treatment and a wide size range; it is less comfortable in real heat. For a women's top, the Under Armour Women's HeatGear Armour Scoop Tank uses super-light HeatGear fabric with mesh ventilation zones and dries quickly, which suits warm races; its compression fit will not suit every body, and sizing runs small, so check the chart. Our moisture-wicking running shirts guide compares more options.

Sports bras deserve the same attention as shoes. Wear one you have done long runs in, check that the band does not ride up when wet, and put anti-chafe balm along the band line.

Shorts or tights

Shorts suit most half marathons above about 40°F. Look for a waistband with an internal drawcord that stays put when it gets wet, a liner or a tight-fitting design that does not ride up, and at least one secure pocket. Inseam length is personal: split shorts give freedom of movement, while a 5-inch inseam covers more of the inner thigh, where chafing starts.

The Brooks Chaser 5" Running Short is a women's short built around exactly that: DriLayer fabric, a 5-inch inseam for thigh coverage, and an adjustable waistband with storage. It is heavier than some shorts at the same price. See our best running shorts for women for lighter and cheaper alternatives, or browse men's 5-inch running shorts if you need a men's pair.

Tights make sense below about 35 to 40°F, or for runners who chafe no matter what. Choose a pair with a drawcord and a back or side pocket, and make sure they do not sag at the knee when wet.

Socks

Blisters are the most common reason a good race turns into a limp. Wear thin-to-medium synthetic or merino socks that you have run in with your race shoes, never cotton. Trim your toenails a couple of days before the race rather than the night before, so any tender spots have time to settle.

Compression socks are optional. Research on whether they improve race performance is mixed, but some runners like how they feel on long efforts. If you already train in them, the Swiftwick Aspire Twelve is a thin, knee-high compression sock that fits well in snug racing shoes, with minimal cushioning underfoot. If you have never run long in compression, race day is not the time to start. Our compression socks for running guide explains the options.

Cold Starts: Sleeves and Throwaway Layers

The smartest cold-weather strategy is to start warm and finish light. Instead of a jacket you will carry for 13 miles, use layers you can remove or discard.

Arm sleeves are the most flexible layer in running. Wear them with a short-sleeve shirt at the start, push them down to your wrists after a mile or two, and pull them back up if the wind picks up. The Nike Pro Dri-FIT Sleeves 4.0 use moisture-wicking fabric with UPF 50+ protection, which also makes them useful on sunny races; the sizing runs small, so check the chart before ordering. Our arm sleeves for running guide covers other picks.

Throwaway layers keep you warm in the corral. An old sweatshirt, a thrift-store fleece, or a pair of cheap cotton gloves works well, because you will shed them once you warm up. Many large races collect discarded clothing along the first miles and donate it; check your race guide for its policy, and toss layers to the side of the course, never in front of other runners. A large trash bag with holes cut for your head and arms makes a free wind and rain poncho for the wait.

Gloves are worth wearing below about 45°F. Hands get cold long before the rest of the body, and thin gloves are easy to tuck into a waistband once they come off.

Hats, Headbands, and Sunglasses

A cap or visor keeps sun and rain off your face. A headband keeps sweat and hair out of your eyes, which matters more than it sounds by mile 9. The Lululemon Fly Away Tamer Headband is a sweat-wicking, reversible headband that is soft against the skin; it is pricey for what it is and can leave a mark if worn for hours. Our running headbands guide has cheaper options.

On a sunny course, sunglasses reduce squinting and eye strain. Our sports sunglasses guide covers pairs that stay put when you sweat. Wear sunscreen on your face, shoulders, and the backs of your arms and neck even on cool, bright mornings.

How to Prevent Chafing

Chafing happens wherever skin rubs against skin or fabric while wet, and a half marathon gives it plenty of time.

• Apply anti-chafe balm generously to the inner thighs, underarms, sports bra band, waistband line, and anywhere a seam sits. Reapply on long, hot races if the course has medical stations with petroleum jelly.
• Protect nipples. Men in particular should use balm, tape, or nipple guards; a technical shirt soaked in sweat rubs hard over 13 miles.
• Remove tags or choose tagless shirts, and check that no seam sits directly under the arm.
• Choose fit over looseness. Snug, flat-seamed fabrics move with you; baggy fabric bunches and rubs.
• Skip cotton. It holds sweat, gets heavy, and turns abrasive.

After the race, shower promptly and wash your kit; our how to wash workout clothes guide explains how to keep technical fabrics from holding odor.

What to Carry: Pockets, Belts, and Fuel

Most runners need to carry three things: fuel, a phone or key, and sometimes a small card with ID and emergency contact details. Plan where each item goes during your dress rehearsal.

• Fuel. Carry the gels or chews you practiced with in training, on the schedule you practiced. A half marathon takes most runners between 1.5 and 3 hours, so many will want at least one or two gels.
• Phone and key. A zip pocket on shorts or tights, or a slim running belt, keeps them from bouncing.
• Bib. Pin it to the front of your shirt so it is visible, or use a race belt if you plan to shed a layer over it.

If your shorts have no secure pocket, browse slim running belts and try one on a long run before the race.

Race-Day Checklist

Lay everything out the night before, so race morning is only about getting dressed and eating breakfast.

Item	Why it matters	Pack the night before?
Race bib and safety pins, or a race belt	You cannot start without it	Yes
Shoes and socks from your long runs	Prevents blisters and surprises	Yes
Shorts or tights, a top (a technical tee or a light tank like the Under Armour HeatGear Armour Scoop Tank), and a sports bra, all from your long runs	Prevents chafing and slipping	Yes
Anti-chafe balm	Apply before you get dressed	Yes
Fuel (gels or chews)	Keeps energy steady after the first hour	Yes
Arm sleeves, gloves, or a throwaway layer	Warm in the corral, easy to shed	Check the forecast
Cap, visor, or headband	Keeps sun, rain, and sweat out of your eyes	Yes
Sunscreen	Protects skin on long, exposed courses	Yes
Phone, key, and ID card	Safety and getting home	Yes
Dry clothes and warm layer for after	You cool down fast once you stop	Yes, in a gear-check bag

How We Chose

Every product here meets four criteria: technical, non-cotton fabric; features that matter over 13.1 miles, such as flat seams, secure waistbands, and pockets; flexibility across a range of race temperatures; and a fair price for what it does. Product details come from each Amazon listing and from our existing category guides to running shirts, women's running shorts, compression socks, arm sleeves, and headbands. Each item was in stock with a current price at our latest Amazon listing check on September 11, 2026. This is a buying guide, not a new hands-on review, so fit and comfort still depend on your own long-run rehearsal.

Frequently Asked Questions

Should I wear shorts or tights for a half marathon?

Shorts suit most races that start above about 40°F, because you warm up quickly. Tights make sense below about 35 to 40°F or if you chafe badly in shorts. Whichever you choose, wear a pair you have already done a long run in.

What should I not wear to a half marathon?

Avoid anything new, anything cotton, and heavy jackets you will end up carrying. Also skip the unwashed race shirt from the expo; its seams and fit are unknown, and there is no time to find out mid-race.

Should I wear the race shirt during the race?

Most experienced runners do not. Race shirts are new and unproven for chafing, and you have no idea how they behave when wet. Wear it for the celebration afterward instead.

How many layers should I wear for a cold half marathon?

Usually one fewer than feels comfortable standing still. A long-sleeve technical top, or a short-sleeve shirt with arm sleeves, plus gloves and a throwaway layer for the corral, covers most races down to about 30°F. Add a light wind layer below that.

Are compression socks worth it for a half marathon?

They are optional. Evidence that they improve race performance is mixed, but some runners like the supported feel over long distances. Wear them on race day only if you have already run long in them.

The Bottom Line

The best half marathon outfit is the one you have already proven on your longest training runs. Dress for 15 to 20°F warmer than the start, keep cotton out of your kit, protect every chafe point with balm, and use sleeves and throwaway layers instead of a jacket on cold mornings.

If you need to fill gaps before race day, the Under Armour Iso-Chill Run Short Sleeve suits warm races, the Under Armour Tech 2.0 Tee is the budget shirt for mild weather, the Under Armour Women's HeatGear Armour Scoop Tank is a light, quick-drying women's top, the Brooks Chaser 5" is a secure women's short with thigh coverage, the Swiftwick Aspire Twelve is for runners who already like compression, the Nike Pro Dri-FIT Sleeves 4.0 handle cold starts, and the Lululemon Fly Away Tamer Headband keeps sweat out of your eyes. Buy them early enough to try them on a long run first.