15°C is at the warmer end of the chilly range (10–16°C); you can go a notch lighter than the middle of this band.
In an average year, 15°C turns up in April, May and October. Those months share this temperature, so their outfits carry over directly.
Compared with 14°C you can drop a layer, and from 16°C upward you can leave the outer layer at home more often.
What 15°C feels like in different conditions
- In wind12°C
- With wind, 15°C feels closer to 12°C — that's the call for one more layer.
- When humid16°C
- High humidity pushes 15°C toward 16°C — look at breathability before thickness.
- Morning → afternoon9 → 18°C
- On a swinging day, pick outerwear for 9°C and your base layer for 18°C.