What to wear running
What to Wear Running in 45 Degree Weather
A general guide. For your exact conditions, check your city.
A long-sleeve top is the sweet spot, with shorts or light tights below. Bring light gloves and an ear band you can stash once you warm up.
The short version
Forty-five degrees is cool running weather where most people want a long sleeve and shorts, or a short sleeve with arm sleeves, plus light gloves for the first mile. It is a comfortable temperature, so avoid overdressing.
Read more: the full guide›
At 45°F a long-sleeve shirt over shorts is the default, with light tights for runners who feel the cold in their legs. Arm sleeves are a flexible alternative to a long sleeve, since you can push them down once you warm up. Gloves are optional but handy for the first mile, and a headband or cap covers the ears if the breeze is up. A thin windbreaker is useful to stash in a pocket or tie around your waist rather than wear from the start.
The common 45-degree mistake is underestimating how quickly you warm up. Starting out in a jacket, long sleeve, and tights feels cozy for two minutes and miserable for the next forty. Dress so you feel slightly cool when you step outside. Another mistake is forgetting the wind, which turns a pleasant 45 into a raw one: a 15 mph headwind can make it feel like the 30s, so a light shell is a sensible piece to have.
Pace and distance decide whether you wear that long sleeve. A long, easy run lets you stay comfortable in sleeves the whole way, while a workout is usually better in a short sleeve with arm sleeves you can discard. Humidity and drizzle change the equation, because damp 45°F air takes heat from your body faster than dry air does. In those conditions, add a light waterproof layer and a cap with a brim.
Sources
This guidance is grounded in published sports-medicine and weather-service sources, not opinion. General advice for healthy adults, not medical advice: trust how you feel over any chart.
- ACSM: exercising in the cold: American College of Sports Medicine guidance on cold-weather exercise, including the principle that runners dressed for standing still are overdressed once moving.
- REI: cold-weather running layers: REI Expert Advice on the base, insulating, and shell layering system, and starting a touch cold so you are comfortable once warmed up.
- Exercise thermoregulation review: American Physiological Society review of how the body sheds heat during exercise: core temperature and sweat rate rise with effort, pace, and duration.
- NWS wind chill chart: NOAA and National Weather Service wind chill chart, the basis for treating wind as a major driver of how cold a run actually feels.
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