Shorts or long trousers — it's the same decision every morning, and the thermometer alone doesn't settle it. Two 19°C days can feel completely different. One of them sends you out in shorts, the other is clearly a trousers day.
The threshold is the feels-like temperature
The number that matters isn't the air temperature but the feels-like temperature: the reading once wind, sun and cloud cover are taken into account. For most people the switch happens around a feels-like of 15°C. Above that shorts become pleasant, below it most people reach for trousers.
That line is personal, which is why KorteBroekAan.nl works with four settings:
- Weakling: shorts only above a feels-like of 20°C
- Average: feels-like above 15°C
- Daring: feels-like above 12°C
- Legend: feels-like above 10°C
What shifts the threshold
Wind is the biggest factor. A moderate 20 km/h takes off around 3 degrees; a firm 35 km/h costs 6 to 7. Cloud cover itself only removes about a degree compared to the same day without clouds — the real loss is what it hides, because full sun on your skin adds 4 to 8 degrees. The gap between sun and cloud is far bigger than the gap between cloudy and cloudier.
Rain works differently again. Wet clothing cools your body much faster than dry clothing, and wet legs in shorts feel noticeably colder than dry ones. High humidity at summer temperatures does the opposite: the heat has nowhere to go, and shorts become less of a choice and more of a necessity.
| Air temperature | Sunny, light wind | Overcast, 20 km/h wind |
|---|---|---|
| 15°C | ~20°C — shorts work | ~11°C — trousers |
| 18°C | ~23°C — shorts | ~14°C — trousers |
| 20°C | ~25°C — shorts | ~16°C — borderline |
| 22°C | ~26°C — shorts | ~17°C — usually still fine |
Can you wear shorts today?
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What you'll be doing counts just as much
The same 17°C is comfortable on a bike and too cold on a café terrace. Moving produces extra body heat and pushes your personal threshold down by a few degrees. Standing still — waiting for a bus, watching from the touchline, sitting on a bench — and you feel the wind far sooner.
Duration matters too. Ten minutes to the shop at a feels-like of 12°C is nothing. Four hours outside at that same 12°C is a different proposition, because your body stops keeping up with the heat it's losing.
Then there's shade. Step out of the sun on an 18°C day and the feels-like drops 5 to 6 degrees immediately. A day that is shorts weather in the open can be a trousers day in woodland or between tall buildings.
Morning or afternoon changes the answer
Weather apps show the daily maximum, and you don't reach it until mid-afternoon. In spring there are 7 to 10 degrees between 7am and 2pm. Leave early and come back late and you're dressing for two different days: use the maximum if you're mainly out in the afternoon, and plan for the edges of the day if you set off early or stay out into the evening.
When it genuinely is a long-trousers day
Some days shorts simply aren't a good idea, and there's no point pretending otherwise. Below a feels-like of 12°C, even people who reach for shorts easily end up cold. The same goes for steady rain, for wind above 35 km/h, and for any day that involves standing around outside for a long stretch.
Season plays a part as well. 18°C in May feels like a release; 18°C in September feels chilly, because your body has adjusted to the warm weeks behind it. The thermometer is identical, your experience isn't.
Conclusion
Look at the feels-like rather than the air temperature, and adjust for what you'll be doing and how long you'll be out. Above 15°C shorts are fine for most people; once it slides towards 12°C with wind or rain on top, trousers are the sensible call.
Learn more
Read next
Can I wear shorts at 12 degrees?
12°C is cold by most standards. Whether shorts are still an option depends heavily on sun, wind and how much you're moving.
Can I wear shorts at 15 degrees?
15°C is right at the tipping point. Whether you can wear shorts at that temperature depends on wind, sun and how your body has adapted to the season.
Can I wear shorts at 18 degrees?
18°C is the threshold many people use for shorts. But with the right conditions, 18°C is perfectly good shorts weather.
Can I wear shorts at 19 degrees?
Is 19 degrees warm enough for shorts? At 19°C sun and wind decide almost everything: from 25°C in the sun to 12°C in the wind.
Why 20 degrees is not always shorts weather
20°C sounds like it should be comfortable. And often it is. But add enough wind or cloud cover and it stops feeling that way fairly quickly.