A 2 year old usually needs a diaper change every 3 hours to 4 hours although it can vary from kid to kid.
Not all 2 year olds use the same amount of diapers as each one of them are different in the amount they pee and when they pee.
A 2 year old should have a wet diaper at least every 4 to 6 hours.
However all kids are different and they pee at different times and different amounts.
Not every 2 year old pees the same time or pees the same amount.
Some 2 year olds can go 3 to 4 hours before they pee and have a wet diaper.
As long as your 2 year old is having a wet diaper every 4 to 6 hours they are likely okay.
Just make sure the 2 year old is getting enough to drink and staying hydrated.
Also when it's hotter outside the 2 year old will pee less as they sweat more and so less urine will be outputted which is normal.
Some days my 2 year old son has a wet diaper every 3 hours and sometimes his diaper stays dry for 4 hours and then he pees at once.
So some days he goes through 4 diapers a day and then some days he only needs 3 diapers per day.
During the hotter months he goes through less diapers than in the cooler months even though he's drinking plenty of fluids.
It's normal.
Just check the 2 year olds diaper every few hours to see if it's wet enough and if the 2 year old has not had a wet diaper in 8 hours or longer then they may be dehydrated.
If the diaper is just a little wet then there's no need to change it and you can wait a few more hours between diaper changes.
Not every kid goes through the same amount of diapers which is normal.
As long as they are wetting the diaper at least every 4 to 6 hours then they are likely okay.