How to let my meteor aim more accurately?

When I cast meteor it very often miss the target. Many times the enemy is near but the meteor aims at somewhere in distance, where there is no enemy at all.
Meteor's "range" is 18 blocks, what this mean?
Wiki says meteor has a 2 block auto-aim radius, what this mean?

 

"Range" means if you aim meteor into the distance, it will cast 18 blocks away.
2 block auto aim radius means if you aim a meteor and it's within 2 blocks of an enemy, it will aim directly on the enemy, whereas if you aim it 3 blocks from an enemy, for example, it would just aim 3 blocks away from it and not directly on it.

 

Thanks! Is it like I should aim at the block under the enemy instead of aim at enemy's hitbox?

 

I usually aim at the ground near the enemy, I don't remember how accurate it is when aiming at the enemy's hitbox (because I don't do it that often). You can try to see which is more consistent.