20°C is above the ideal 16–18°C range, but not dramatically. Most people will still fall asleep — it's staying asleep through the early hours that becomes harder, because your body can't complete its natural cooling cycle.

Dew point is 16°C — not extreme but enough to make the warmth feel stickier than the temperature alone suggests. The gap between temperature and dew point is what determines whether the air feels fresh or muggy.

The air barely cools overnight — just 0.0°C between bedtime and 4am. Your body's circadian rhythm expects a temperature dip during the night. When the environment doesn't provide one, sleep becomes lighter and more fragmented, even if you don't fully wake.