Unexpected behaviour from if statement

I have a simple if statement as follows:

if (!state.wasGroundedLastFrame && _speed.y > 0){
    _newPosition.y += _speed.y * Time.deltaTime;
}

But as you can see in the image below that it’s entering the block even when _speed.y is less than 0. What could I be doing wrong?

I using MonoDevelop with Unity in C#