My X (Twitter) feed has recently featured a number of maps that delineate and rank climate zones in the United States based on how comfortable or idyllic they supposedly are. I find these maps interesting but inevitably problematic. One of the most intriguing is the “Camelot Climate Index,” devised and mapped by meteorologist Jan Null. The person who posted it on X (VB Knives) claimed that it is a “legit climate quality map, which closely tracks to average preferences,” further arguing that it “rewards warm and sunny [climates].” I objected in my reply, noting that the map puts cool and foggy San Francisco in second place, after San Diego. I also foolishly misquoted Mark Twain, who is often said to have quipped that “The coldest winter I even spent was a summer in San Francisco.” Twain never made this statement, but it does seem fitting.
Embarrassed by my misquotation, I decided to examine the map in more detail. What I found is a well-considered and modest effort by a knowledgeable meteorologist to map his own climate preferences based on rigorous quantitative analysis. As Null frames his “Camelot Climate Index:
In this 1960’s musical King Arthur professes that Camelot has a perfect climate all the year; and by royal decree at that! But actually an “ideal” climate is extremely subjective, with one person’s idea of perfection being met with disdain by others. Some individuals may want warm beach weather all year round, while four distinct seasons are most desirable for others. What follows is just one person’s (the author’s) idea that an ideal climate is sunny and relatively mild with few extremes in temperature, humidity or precipitation. …
Null also notes that his map “is rudimentary at best given the limited dataset,” and concludes by admitting that other climate observers would come up with very different maps: “If a similar project was done by a storm chaser it might be called the Oz Climate Index with a bias towards the number of thunderstorm days, hail and tornadoes.”
At any rate, I have posted Null’s original map below. To make it more legible to those unfamiliar with isoline maps, I have colored in the areas between the lines, as can be seen in the second map.
Although my own climate preferences are quite different from those of Null, I admire his index and resulting map. He has taken on a complex task and has produced an interesting and informative map. But if I were to make a climate map based on the song “Camelot,” it would have a very different appearance – if it could be produced at all – because I would interpret the lyrics in a more literal manner. This is again merely a subjective preference, but exploring it might still prove worthwhile.
First, I would give more weight to the first climate-related line: in Camelot, “June, July, and August cannot be too hot.” As a result, the interior southwest would have a lower ranking on my hypothetical map than it does on Null’s. He gives Las Vegas, for example, a measurement of 78, the sixth most favorable in the country. But with an average July high temperature of 104ºF and an average low of 82ºF, Las Vegas seems distinctly “uncamelotic” to me. Its forecast high temperature for this coming Saturday is a blistering 115ºF, with a low of 89ºF.
The song also stipulates a relatively mild winter, one that does not begin until December and ends “March the second on the dot,” and in which there is a “legal limit to the snow.” But although a long and snowy cold season is clearly precluded, the lyrics imply that Camelot does have a distinct winter and does receive snow on a regular basis. As Null acknowledges, many people like a climate with four distinct seasons, and the song’s King Arthur was apparently one of them. By my reading, the coastal strip of southern and central California – which is placed in the top position on Null’s map – would have to be downgraded due to its lack of a real winter.
Precipitation is a particularly tricky issue in determining the climate of Camelot. On Null’s map, a large number of days with measurable rainfall counts against an idyllic climate. As a result, the driest area of the country, the southern interior southwest, has a relatively high ranking, while Washington’s Olympic Peninsula and Hilo, Hawaii are given very low rankings. But the song says nothing about total precipitation, specifying instead that in Camelot’s unique micro-climate rainfall occurs only at night. The common image of Camelot, it seems to me, includes a verdant environment, once that necessarily receives regular rainfall throughout the growing season. By this criterion, which is admittedly not specified in the song, the arid, semi-arid, and Mediterranean climate zones of the American west would have to be downgraded. It is also noteworthy that the areas of the United States that get more rain in the night than during the day include the north and west facing slopes of the Hawaiian Islands and the Great Plains. If this metric were included in the index, the “big” island of Hawaii would have to be upgraded, as would the northern Great Plains.
Regardless of what the song stipulates, my biggest problem with the innovative “Camelot Climate Index” is the way that it groups together areas with dissimilar climates. Eureka, California and Las Vegas, Nevada, for example, have almost identical scores, ranking in the fifth and sixth highest positions nationwide. Yet their climates are very dissimilar. The highest July temperature ever recorded in Eureka is a mere 77ºF, which is 5ºF lower than Las Vegas’s average July low temperature. Cool, cloudy, and windy Eureka, moreover, receives more than an order of magnitude more precipitation than arid, sun-blasted Las Vegas (40.4 inches as opposed to 4.18 inches). I would not want to live in either place, as the former is too cool and cloudy in the summer and latter too hot and dry. Other people, of course, have different preferences. But I doubt that many would view the two cities as having equally appealing climates.