I said this a year or 2 ago when we were talking about MDT's readings. I drive the river route to Conestoga every day, and it's usually a few degrees warmer RIGHT along the river on 441 than it is away from the water. That, combined with all of the asphalt makes their reading completely believable to me. (at least the warmer night temps compared to those surrounding HIA)
I flew out of HIA one morning in 2018 when there was about 2" of fresh, but very wet snow at the 283/Airport connector exit. Those who know it realize that it's only about 1.5-2 miles from the terminal and the river. That morning, by the time my wife dropped me off at Departures...there was no evidence that it had snowed. It was too warm to accumulate.