I was encouraged to see that I wasn’t the only person fascinated by weather extremes in So Hot, So Cold. Reader "zxo" had been thinking along similar lines a few months ago and created a series of related maps. One of those compared the differences between the highest and lowest temperatures recorded in each state. Check it out. It even showed the approximate location where each state record was set. I’ll use that as the basis for the remainder of this article. Thanks for the inspiration, zxo.
The Weather Channel took a similar tack in July 2013. They had the ability to produce prettier graphics with professional equipment although I still find zxo’s all-encompassing map more useful than trying to scroll through a strip of fifty images. However the Weather Channel did provide three fairly intuitive reasons to account for states with the most extreme differences of extremes:
- A wide range of elevations, e.g., "California… with Death Valley sitting 282 feet below sea level while 14,000-foot mountain peaks sit less than 100 miles away"
- A long distance from large bodies of water that "heat and cool slowly, keeping adjacent land areas milder in winter and cooler in summer"
- Latitude. Variability increases as one moves away from the equator, with additional hours of sunlight in summer and longer nighttimes in winter
As before, I’ll use Wikipedia’s chart of U.S. state temperature extremes. I’ve noticed slight variations between this list and some others I’ve consulted on the Intertubes. I’m not able to compare these against the official list at National Oceanic and Atmospheric Administration due to the government shutdown (October 2013) so I’ll have to consider Wikipedia close enough as a proxy and plow forward.
Fort Yukon Sign by Mozul, on Flickr
via Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0) license
My rule of thumb is to begin with Alaska reflexively whenever I play "guess the state." It seems to be the one that provides the geo-oddity answer more often than not. It would appear to score very high on all three factors for this exercise too, ranging from sea level to 20,237 ft (6,168 m) at Denali; having parts of the state hundreds of miles distant from the nearest shoreline due to its immense size; and featuring latitudes farther removed from the equator than anywhere else in the nation. As expected, Alaska scored very well with an extreme temperature range of 180°F (100°F / 38°C at Fort Yukon on June 27, 1915 and -80°F / -62°C at Prospect Creek on January 23, 1971). However it’s not the champion, nor does it even capture second place.
(A) Medicine Lake to (B) Rogers Pass
Would you believe… Montana? I was surprised. Sure, one would expect it to score high on all three criteria although I didn’t expect it to beat Alaska, and rather convincingly too. Montana’s difference of extremes was an astounding 187°F. The mercury rose to 117°F / 47°C most recently on July 5, 1937, at Medicine Lake, and previously at Glendive in July 1893. Both of those places are found at the far eastern edge of the state, a semi-arid extension of the Great Plains baked by searing summer heat.
Medicine Lake by cm195902, on Flickr
via Creative Commons Attribution 2.0 Generic (CC BY 2.0) license
The etymology of Montana traces to the Spanish word Montaña referring to a mountainous area, and there are plenty of higher elevations on the western side of the state. It was at Rogers Pass where Montana set its lowest temperature extreme on January 20, 1954, a bone-chilling -70°F / -57°C. Rogers Pass is actually one of the lower elevations through Montana’s mountains and over the Continental Divide (5,610 ft / 1,710 m) — after all that’s why it’s called a pass — so one can only imagine what the temperature would have hit had it been recorded on any of the nearby summits another thousand feet up, instead.
North Dakota scored higher than Alaska too, at "only" 181°F difference. The state recorded 121°F / 49°C on July 6, 1936 at Steele and -60°F / -51°C on February 15, 1936 at Parshall. Hawaii, perhaps more obviously, recorded the least amount of difference, a mere 83°F. Hawaii was also the only state that had never recorded a temperature below zero on the Fahrenheit scale.
All of these extreme thoughts led me to wonder about the maximum difference for a single location. Unfortunately there aren’t handy lists of such things available. My initial guess would be Fairbanks, Alaska, with a difference of 159°F (99°F / 37°C and -60°F / -51°C). Another site said 96°F and -62°F so who knows? It’s a big difference, whichever source happens to be correct. Perhaps there are location even more extreme found elsewhere in Alaska, or maybe in Siberia or the Canadian Arctic?