The heat impact was detectable up to a third of a mile, or about five city blocks, distant from the perimeter of datacenters.
A 1 degree Fahrenhiet (0.6C) for 1/3 of a mile or 500m? Pretty minimal impact if you ask me.
And it would be helpful to compare to other industrial sites. I can walk by a building's airconditioner unit and notice a significant temperature increase.