It is not necessary to use nitrogen but it does help in keep the tire temps/pressure constant but for street driving but again it is not necessary.
I have used nitrogen in the track tires on my car when i go to the track in the hot humid Florida weather and my tire pressure stays where I need it.
If you live in dry air and fill your tires under low humidity you will notice less raise in tire pressure but the water in the air is what gets hot and increases tire pressures.