Southern Utah Weather Station near Kanab, UT
This page is collection of data, links, and general axioms about climate in general and the southwest in particular.
Kanab sits on the northern edge of the Arizona Strip, a tract of mostly grassland 130 miles long, bounded on the south by the Colorado River and - according to a map - on the north by the Utah border. However in geologic reality the northern terminus of the Arizona strip may be considered to be the Grand Staircase of southern Utah and northen Arizona .
The Kanab macro climate is classified by the Koppen system as BSk. (Wladimir Koppen was a Russian meterologist and climatologist who was the first to classify world climates...more about the BSk distinction follows later). Kanab is an arid climate but it is not a desert. Many people classify the entire southwest as a desert presumably because it is hot and dry and has a lot of rattlesnakes. However these are not fully adequate descriptors by themselves. For example the alpine face of the eastern Sierra mountains in California is hot and dry and they have many rattlers but I have never heard anyone call Mamoth Mountain a desert. Also my guess is we have fewer days over 90 degrees and 100 degress in Kanab than most of the southwest areas you may be thinking of. The same holds true for precipitation.
Deserts (listed for distinction) -
Deserts are usually described as having two or more of the following attributes:
1) less than ten inches of annual precipitation.
2) extremely long and hot summers
Kanab gets 13.5 inches of precipitation per year and has a very short summer and winter. The only one of the three above listed desert attributes real familiar to Kanab is aridity (#3) which keeps humidity very low.
As an aside it is worth noting that rainfall in the desert is sporadic, year to year. For example the annual precipitation for Barstow CA is about 4.50 inches but that figure is a mean average and does not take into account all of the years of 1.00 inches or less. This year (2005) Barstow got nearly 15 inches which brings the mean average closer to the 4.50 figure. However the median average in Barstow may be closer to 2.00. Kanab's median is much closer to the mean. A cursory check shows a median annual precipitation of 9.56 inches.
As mentioned above the climate here in Kanab is Koppen BSk. In Russia the area east ot the Urals and south along the Russian border is arid grasslands called "steppes" and it is presumed that this is the area Koppen used for the BS classification. Incidently, the same geography and climate makes up most of the Colorado plateau.
Agriculturally steppes are suited for irrigational farming and animal grazing and that's about it. When you look out onto millions of acres of this land today you cannot see much of the grassland that defines steppes. However at one time grass covered eveything as far as you could see south of Kanab. Overgrazing has allowed the sage to overtake the grasses and today you cannot see much of the steppes distinction. If you are lucky enough to find some land that has not been grazed for 100 years or so you will see a grand green carpet of grasses in the spring and knee high dried grass in the fall. But with only scattered sage brush.
Another aside to note: Left to her own devices Mother Nature keeps sage brush intrusion at bay with natural calamity. Lightneing fires burn the plane regulary which takes everything dead to the ground. Grass comes back first, fast, and thick making it harder for the sage to spread.
In Kanab we sit on the very northern edge of a steppes contour. Pretty much everything south of us is steppes but we are situated on a transition zone between steppes and woodlands. Common woodlands here are called PJ forests (Pinion and Juniper) . The woods can be very thick with these short trees which are rarely more than 18 feet in height. On and behind our fifteen acres of land east of Kanab is PJ forest with a ponderosa pine I know of (poor young critter is dead now). The cliffs above us are just another 600 feet higher but there are a few ponderosa up there too. A few miles north and the juniper gives way to 100 percent ponderosa and pinion pine. Above that is spruce and fir and aspen
Still another aside to note is that there are a lot of towns and geographical features in Utah using the name of the cedar tree. Cedar Breaks, Cedar City, Cedar Mountain, etc. The Mormon Settlers misnamed the juniper trees as "cedar" trees and the name has stuck. I am not sure I even know what a "real" cedar tree looks like.
As mentioned there is an annual precipitation average of 13.5 inches in Kanab and the length of summer is very short. On average there are 61 days per year over 90 degrees *. The amount of precipitation coupled with the rather short summer results in retaining much of the moisture from snow and rain. This retention dictates a totally different biome than that of a typical desert. The preponderance of precipitation comes in the form of snow and rain from January to March. and monsoons in August and September.
The winters are cold by Southern California standards (my home state) with an average minimum temperature in January of 21 degrees. The sun shines bright in the winter and warms with radiation ( radiation can warm your body if not the air so it is quite comfortable in short sleeves at 45 degrees as long as you dont get into shade). There are two very moderate and quite beautiful seasons in Spring and Fall.
Note: the temperatures given above and below are for Kanab city proper. Our Rancho is, on average, 1.5 degrees warmer in summer and 2 degrees colder in winter. See anomalies below.
Following are Western Regional Climate Center data sets that show temperature and precipitation averages for Kanab.
Days over 90 degrees in an average year and the record high temperature.
Long Beach, Ca 22 days 90+, record high 111
Kanab, Ut 61 days 90+, record high 108
Pomona, Ca 68 days 90+, record high 113
Winslow, Az 72 days 90+, record high 109
Corona, Ca 75 days 90+, record high 114
Sedona, Az 93 days 90+, record high 110
Fresno, Ca 106 days 90+, record high 112
Victorville, Ca 107 days 90+, record high 116
San Bernardino, Ca 108 days 90+, record high 117
Cottonwood, Az 115 days 90+, record high 114
Saint George, Ut 124 days 90+, record high 117
Mesquite, Nv (Bunkerville) 149 days 90+, record high 119
Phoenix, Az 168 days 90+, record high 121
Inches of precipitation in an average year.
Sedona, Az 17.95
Kanab, Ut 13.49
Long Beach, Ca 11.93
Corona, Ca 11.49
Newport Beach, Ca 11.38
Fresno, Ca 10.89
Cottonwood, Az 11.84
Saint George, Ut 8.20
Phoenix, Az 7.95
Winslow, Az 7.83
Mesquite, Nv (Bunkerville) 5.97
Victorville, Ca 5.44
Selected cities of friends and family: more complete climate data
This section is a collection of information gleaned from meteorologist friends and acquaintances and textbook climatology.
Climate is not weather. Climate is a collection of weather data. There are simply too many out-of-the-ordinary weather conditions to establish a climate profile from a single weather event. For example it could be 100 degrees in Los Angeles for a week and only 90 degrees in Kanab. This does not indicate a hotter climate in Los Angeles. Only data collected over decades will establish a climate type. Climate is the average of weather observations.
The National Oceanic and Atmospheric Administration (NOAA) is the only authentic agency for weather and climate data. The National Weather Service (NWS), as a division of NOAA, is the agency responsible for the collection and dissemination of the data. Regional Climate Centers such as the Western Regional Climate Center (WRCC) are government-sponsored agencies whose task is to archive weather data. These are either separate NOAA divisions or are run under grants by a university.
NWS collects weather data a number of ways. From satellite, ships radio, airports, balloons, radar, weather stations, and more. Weather stations are certified and calibrated by NWS. They are placed in various locations around the country (they are not, necessarily, large and expensive stations as my weather station qualifies under NWS criteria and cost less than $400). There are three ways that the weather station can report data: Real-time, chart reader, and by report.
Real-time is a weather station that automatically radios or telephones in the data. These are the stations that most of the local TV channels use. They can be identified by call letters such as KLAX or similar.
Chart reader is the old fashioned style that is setup to use a pen and ink to chart a graph to paper. The paper is collected periodically and the data transferred manually to a computer.
Collecting by report means that a person calls in once per day and reports the vitals. This is the most common type of NWS station. The Kanab station works like this.
The following two rules about temperature reading and climate have been refined from texts, discussions with peers, other weather station owners, and lots of news group discussions (sci.geo.metorology and Yahoo groups)
Calibrated weather stations placed in calibrated environments produce equal results. What this means is, if you are going to do a comparison, it is important to make sure the weather station environments are the same. If one weather station is placed on an asphalt parking lot it will read substantially different than if it was placed on the grass of a football field. NWS gives setup criteria, but to my knowledge they do not come out to the site and verify it.
There is an approximate one-degree of temperature change for every 300 feet of elevation change. This was a rule I used as a pilot and data confirms the accuracy (NOAA research results). The way molecules of air exchange heat dictate an environmental lapse rate that is pretty close to linear. However there is no mathematical formula for it. It should be noted that the sun does not warm the air. Air is not a very good collector of solar energy. Instead the sun heats the ground and the ground heats the air near to it while that air heats the rest of the air surrounding it. Also, similar terra at higher elevations absorb just as much heat as lower elevations. However the thinner the atmosphere the longer it takes to heat the air via the pertinent earth mechanism. Ergo, higher elevations (thinner air) lags behind in temperature gain.
NOTE ONE: when applying this rule to towns and cities it should be stated that it only works when the areas being studied are close together. For example; the difference in temperatures between Reno/Tahoe and Victorville/Big Bear follow this rule closely. Just check the elevation then check the average summer temperatures and do the math. However the difference in temperature between Kanab/Denver would not correlate at all since they are not in close proximity (even though they are almost the same elevation).
NOTE TWO: rule two is often non linear in winter.
NOTE THREE: rule two causation is not as simplistic as it is presented. There are many pieces and parts to the environmental lapse rate (see anomalies below). However the upward exchange of heat generated from the earth’s surface and the compression mechanism mentioned are more representative and supportive of the data, in my opinion.
Many anomalies exist in climate data. Weather data from one station to another sometimes defies the simple rules. However, upon close examination and investigation, the data that are suspect can often be rectified. .
Our weather station is calibrated to reflect a precise temperature at our location. So is the weather station in Kanab which reports official data to the NWS daily. However our temperatures sometimes reads one or two degrees higher than theirs. Why? We are nearly 250 feet higher in elevation than the Kanab station and should, by rule, read at least the same if not cooler. The answer to this lies in the environment. The Kanab station is in Kanab city proper. Like every city there are lawns and trees that "air condition" the surroundings through transpiration and shade. For example we have taken hikes down Kanab Creek in the heat of a 95 degree summer day and felt a five to ten degree temperature differential manufactured by the riparian surroundings. Out in our end of the dirt there is no riparian cooling whatsoever. Our station is away from the house and mounted directly over the dirt as dictated by NWS setup standards. Since 99% of the land around here is pretty much like ours this station reflects the temperature of hundreds of square miles around here while the Kanab station reflects the temperature only within the town. So, if you were to issue a unilateral about the climate/weather of Kanab you would have to be precise in how you described the city/county/area. It does make a difference.
A second anomaly I located was the difference in temperatures between Fresno and Bakersfield CA (I lived in Fresno for five years). This was not so much an anomaly as it was a contest. These two cities are constantly at war over who is the hottest. City hall in Bakersfield says Fresno is the hottest and Fresno says the opposite. This is rather humorous since they are both very hot in the summer. It is like arguing which corner of hell is best. But it came to light one day in the Fresno Bee that the weather stations in both cities were being moved around, each city seeking to place their station closer to a golf course or riparian woods to get a lower "published" reading. Once NWS was apprised of this they rectified the situation and today, supposedly, the data are accurate.
Apple Valley, CA is in the Mojave Desert. It is contiguous to Victorville, separated only by the Mojave River. The two are the same elevation and have the same geographical features. The rules dictate that the surroundings of one area so close to another area should have no effect on climate since the elevations are alike. The temperatures of one should be the same as the other. Since Apple Valley has no record with the Western Regional Climate Center I extrapolated data from surrounding areas of Palmdale, El Mirage, Mojave, and Victorville. They are all roughly the same elevation and in the same desert. I used their data and found that their highest and average yearly high temperatures were within one degree of each other. This did not coincide with the only weather station I could find in Apple Valley. The Lewis Center for Educational Research in Apple Valley continually broadcasts temperatures three to four degrees cooler than the surrounding areas. Investigation revealed that the Lewis Center had placed their weather station on their Mana Road campus just across the river from Victorville and within a few hundred feet of the Mojave River. It turns out that the operator of the center, Paul Bunnel, wanted a NOAA certified weather station at that location to collect data on the macro environment that is situated there along the river. If the station was moved back a few hundred yards the temperatures should be the same as Victorville, El Mirage, Mojave, etc. Click here to see pictures of the riparian bottom of the Mojave river adjacent to the Lewis Center (courtesy of Mr. Bunnel)
There are hundreds of examples that break the rules but the rules still rule. Investigation will always show the reason for an anomaly. If anyone can locate a rule-breaker that has no apparent cause I would like to hear about it as I enjoy this kind of sluething. Email