The sleep of a 5-month-old baby
Five months is the age of short naps. You put them down, they sleep exactly thirty minutes, and they wake crying, visibly still tired. It is the number one topic at this age, and it is arithmetic before it is a problem.
A cycle lasts about 55 minutes for a five-month-old, and a short nap stops at the end of the first one. Linking two cycles is a skill that is acquired, usually between five and seven months. Until then, a one-cycle nap is not a failed nap.
The other news this month is better: long nights become genuinely possible. Not guaranteed — possible.
Sleep per 24 h
12 – 16 h
Of which at night
10 – 11 h
Naps
3
Awake window
2 h – 2 h 30
One cycle lasts
~ 55 min
Before putting down
~ 15 min
The key point at this age
What actually helps with short naps
Three levers, in this order. Complete darkness first, because daylight alone is enough to prevent the move into the next cycle. Then the awake window: at five months it sits around two hours, and a baby put down too late or too early will take a short nap. Finally, being there as they surface: if you are in the room when they start stirring, a hand on them and some patience is sometimes enough to send them back under.