The two USHCN stations are in northern Illinois not too far from Chicago. They had the least missing data of the station choices but do have other concerns – Aurora is located at a water treatment plant while the Ottawa MMTS is nearly in a bank of trees.

The trend in Ottawa over the last sixty years is flat to perhaps slightly down. Aurora was nearly flat, too, until about 2000, when the number of warm nights increased sharply. Hard to say if that is microclimate-driven by treatment plant activity or part of a weather-driven trend – I’ll check a few more stations. Regardless, there seems to have been little to no increase in warm nights near Chicago, at least until 2000.

The first is a look at the decades in which summer high temperature records were set. This covers the contiguous US for the three typically hottest months (June/July/August). A single nationwide event would affect the records for one month but not for all three, so this plot should be less-influenced by single extreme events.

The appearance is similar to the record high plot of #127.

Here is a similar plot except that it is for record lows in December, January and February:

There appears to be a modest downward trend in extreme cold events.

(Note: The final bar in each chart covers 2000-2003 (records posted as of May 2004) and is prorated so as to make an apples-to-apples visual display.)
Here’s the combination of the two:

Conclusion – the 1930s in the US were rough.

Note: The trendlines for all three graphs are essentially flat (no trend) if the prorated early 2000s are excluded from the trend calculations.

Perhaps it’s a bit of a surprise that the 2000s, for all the reported warmth and worry about extreme weather, have set no records so far.

I am gobsmacked! Whatever that means. What is your source?

Great table as well.

The saddest part about “The Day After Tomorrow” is that there is a great action novel by Allan Folsom with the same name that has nothing to do with AGW.

Also, of course, single hot or cold spells (July 1936 and January 1996, for examples) can distort the records.

My view of the data would say that those two periods had a great deal of leverage on the correlation, although I did not bother to analyze it, since my point was to be facetious.

I watched “Day After Tomorrow” the day before yesterday. Whether AGW leads to more hot or more cold is open for debate, but I think beyond a doubt AGW leads to bad movies.

I watched some scenes from “Day After Tomorrow” two days before the day after tomorrow and I was set to wondering if those who are the most sincere advocates of immediate AGW mitigation must wince when they view how overdone this movie is. I have never been able to sit through it start to finish, but if the producers ever need a better rationalization for making it, I will gladly provide the hot/cold correlation – with all due credit to you.

Also, of course, single hot or cold spells (July 1936 and January 1996, for examples) can distort the records.

I watched “Day After Tomorrow” the day before yesterday. Whether AGW leads to more hot or more cold is open for debate, but I think beyond a doubt AGW leads to bad movies.

Not so fast, David. You have shown that the cold to hot state temperature records correlate over the time period used with an Adj R^2 = 0.53 and a slope of 0.371+/- 0.19.

I leave the remainder of this excercise for someone to conjecture that since GW would logically seem to cause extreme hot temperature records to be broken we can expect that that will cause extreme cold records to be broken and we will have the worst of all worlds.

As a corollary we could conjecture that a coolling climate would cause the cold records to be broken and that will cause hot records to be broken and therefore again having the worst of all worlds.

Therefore, one could propose that a nontrending climate, i.e. the status quo, is the ideal.

All to demonstrate that I have had way too much time on my hands of late.