The change from summer to winter nightwear
Short answer: Most people change nightwear by the season, but the temperature of the bedroom is the right measure. Change when you wake up cold or clammy, not by the calendar.
The room rather than the season
A bedroom with the window open all year needs the same nightwear in May and October. Go by the temperature of the room.
Mixed sets
Many people wear a thin top with long bottoms in the transition. That is an easier adjustment than changing the whole set.
Summer
In summer short models and nightdresses are used. See bamboo night shorts for women.
Winter
In winter long sets are used. See bamboo nightwear for women.
For men
See both in bamboo nightwear for men and pyjama bottoms for men.
The bedding changes too
The weight of the duvet matters more than the nightwear. See bamboo bedding.
Storage
Pack away the set you are not using completely clean and dry. See storing bamboo clothing.
How many sets you need over a year
Two thin sets for summer and two long ones for winter cover a whole year for most people. Then you can wash without going short in either season. See nightwear.
Frequently asked questions
When should you change nightwear by the season?
When you start waking up cold or clammy, not by the calendar.
Can you mix short and long?
Yes. A thin top with long bottoms is a common solution in the transition.
Does the duvet matter more than the nightwear?
For the warmth, yes. The nightwear decides how it feels against the skin.