But what about the records for everywhere in the country? Probably you'd want to see them over a decent time interval, too.
I haven't found that historical archive, but I did find a site that posts weekly records as reported to the National Weather Service.
It's interesting stuff - click through to the map, which is interactive. Depending on when you click, you may or may not see the same data (they update their map pretty regularly). This is as of 20 October 2009 04:21 PDT.
Here's what the dots mean:
Red - Record High temperature (highest reading of the day is highest ever recorded) (277 stations)Pretty much everywhere north and east of the Red river saw record cold. The mountain states and Texas saw record heat. Overall, record low beat record high by around four to one.
Yellow - Record High Minimum temperature (lowest reading of the day is highest ever recorded) (527 stations)
Blue - Record Low Max temperature (highest reading of the day is lowest ever recorded) (2958 stations)
Purple - Record Low temperature (lowest reading of the day is lowest ever recorded) (330 stations)
White - Record snowfall (most of these seem to be records due to early date of snowfall, rather than deep accumulations) (143 stations)
Green - Record Rainfall (734 stations)
What does this saw about Global Warming? Nothing, really. However, it's pretty interesting. Run back over 80 years, I think that the records (high vs low) would give a very interesting view of whether we were seeing a hockey stick or not.
Hat tip: Watts Up With That, where there is this very interesting comment:
SMSUnless Global Warming leads to a greater spread between high and low temperatures, this seems highly counter-intuitive. Or there's no clear warming signal. Should be pretty easy to see if the spread is increasing.