(Dujon) I looked at OZBOM, an excellent site, and it confirmed that it was the maxima that were all over 100°F. I suspect the minima were mostly 25° to 30°. In the last few years Adelaide has had a record high minimum of 34°C. To get a minimum of 100°F (37.8°C) you really need quite a stiff breeze to stop the lowest layers cooling and becoming decoupled from the circulation. You get a sandstorm thrown in for good measure, of course. The only place that doesn't seem to need this condition is Death Valley, where there have been several well-authenticated instances of the night minimum being above 110°F. Glad I'm not the weather observer there, or in Ojmjakon, Siberia, January mean -50°C. Yes, fifty. Wrap up well, as my Mum used to say.
[Rosie] Thank you. I must have missed that information, thanks for the clarification. As far as wrapping up well is concerned your Mum's advice sounds like it should have been originally decreed by one of those pesky Yorkshire men (before they subsisted on gravel, of course). ;)
Merry Christmas from your friends in the States. Today in Seattle (where it is still the 24th for another few hours) the weather was truly lovely - a Christmas oddity since we usually receive rain every December. Thanks for inventing MC, and then for letting us with no Tubes play too. =)