The gap between the pristine, gold standard US Climate Reference Network and nClimDiv continues to widen, with USCRN coming in a whopping 0.2F warmer for this summer. Contrary to the narrative widely spun on social media (and even among some in the traditional media), USCRN continues to warm at a faster rate than nClimDiv as more unadjusted/uncorrected biases are allowed to infiltrate nClimDiv. Recently, NOAA replaced temperature sensors, shields, and aspiration fans across its ASOS network, although it's unclear whether this is fully completed [last update was from July 1 and they were over halfway done at that time]. Probably no surprise that this summer saw the widest gap between the two, when ASOS sites make up a sizable portion of the nClimDiv dataset.
The only difference in rankings is while nClimDiv has 2006 as 0.17F warmer than this summer, USCRN has this summer as 0.21F warmer. Also, USCRN has this summer MUCH closer to 2011, 2018, and 2016 - within a few hundredths of a degree. USCRN would also rank 2021 above 1936, subject, of course, to the qualification that this network didn't exist at that time (so it's comparing to the anomalies from nClimDiv dataset).