Yes it does.The oil gets thinner as it warms up
But "Weight" doesn't mean a specific viscosity at a specific temperature.
Actually, it doesn't meant anything.
The correct term is "Grade"
Guys, you gotta STOP using "Weight" or we will always have the Multigrade "W"inter confusion.
A 5W30 performs like a 5W monograde when Cold**, then like an SAE 30 grade when HOT ( KV100 min/max).
What happens at KV40 is quite variable among brands and that is still "fever temperature"
**At least to CCS and or MRV test requirements for oil grade classification.