Just wait until the end of the month when ORD finishes near or above average in January snowfall, despite the month being like +8 lol. Never been anything like that in January for Chicago, as the warmest Januaries all had well below average smowfall... with many producing barely any snow. January 1914 might be a comparison, but this January looks likely to finish even warmer.
I'm not sure how the 6 hour thing came about, but it is what it is. I think it's a reasonable frequency for measurements in most circumstances.