Perhaps someone can explain why these maps don’t show urban hot spots. Is it lack of resolution or homogenization or something else.
I ran across this image recently.
I think what you’re after is the UDEL analysis ( I haven’t gotten familiar with it yet ). This goes to Mosher’s point about the data sets being a model, they are models of how temperatures vary in between actually observed points. The objective analysis scheme makes a difference. I ran into this doing plots for surface obs. Most schemes ( Barnes, Cressman, et. al. ) would draw contours that would violate the station value and forecasters get crazy about that. But there are schemes that treat each point as being valid, which evidently the UDEL uses and you can see hot spots and cool spots.
Of course, if one is emotionally inclined for a particular result to occur, there is subjectivity in which ‘objective’ analysis is correct. ‘The great thing about standards is there are so many to choose from.’