Scott

The weather station was located somewhere on the crater rim and readings were taken continuously. Unfortunately, I do not know the type of instruments used. This was an experiment from ~40 years ago. Because I am so interested in mountain weather, I obtained the temperatures from the NPS Visitor Center in the 1980's. It wasn't until years later learned that the data came originally from a University of Washington Study in the 1970's when I inquired about it in a weather forum and someone provided me the information. It may be best to contact the University itself. I wish I had the extremes for each month, rather than just the averages. Unfortunately, much of the weather data is hard to obtain from non-official stations (including the data for Peter Sinks, the topic of this forum). For Pikes Peak, for example, Larry Dunn compiled all the data by hand in the basement of some weather office in Colorado Springs. For some stations, I painstakingly dug for any information I could gather for the website, so it will be easily obtainable for anyone. For SNOTEL sites, Camp Muir, etc., for example, I don't think averages are available. Daily data is. I actually calculated all that information by hand! Not only that, all the data used to be in metric for the SNOTEL sites and I had to convert it! To show how much work some of it was, here is just one except of one of my hundreds of pages compiled on a random SNOTEL site (Five Point Lake in the Uinta Mountains): http://images.summitpost.org/original/982371.JPG Before the internet, I had to gather data by hand at libraries and archives and I compiled hundreds of notebooks of information. For example, here is a section of one notebook I have on some weather for mountain top locations in the Wasatch: http://www.summitpost.org/images/medium/982372.JPG So, a lot of the data, I had to calculate using any sources deemed accurate. (PS, I am currently trying to put enter the data for the weather station at about 14K on Denali if anyone wants to help!). I do not know what type of equipment was used for recording the weather data; I only obtained the data. I always try to be as accurate as possible with it and it was a lot of work to obtain. I hope that people find my webpages useful as my own motivation is only to share often hard to obtain weather data for remote locations and it was a lot of work to compile. The spreadsheet you were referring to with the mountain data might not look like much, but it was actually a labor of love that took many hours of work over several years to compile. The sources given don't mean that it was a simple google search that provided the data; much of it had to be compiled over a period of several years, and by hand. Information in the official NOAA NOW database is much easier to obtain! All data I have seen indicated that Mount Washington has lower extremes, but Mount Rainier is colder on average, even in winter (though they are more evenly matched in winter). Mount Rainier is more consistently cold in winter, while the temperature fluctuates more on Mount Washington, on both the "warm" and cold sides. During the time the weather station existed on Rainier, for example, the coldest temperature recorded was -36F. During the same time period, Mt Washington either matched or exceeded that reading in three years (-36F in 1971, -44F in 1976, and -38F in 1979) and of course many, many times outside those years. So Mt Washington definitely has lower extremes (and higher ones as well). Even on Pikes Peak, and more so on Rainier though, the temperatures don't get as warm in winter as they do on Mt Washington. The temperature on Mount Washington actually rises above freezing periodically in most winters, and occasionally even rises into the 40's). It doesn't do so on Rainier of Pikes Peak (Pikes Peak has never recorded a temperature as warm as freezing in December, January, and February; I don't know what the winter extreme for Rainier is). So, Mt Washington gets both colder and warmer in winter than Pikes Peak or Rainier, even though the average temperature is a bit warmer in winter on Mt Washington (though it would be interesting to compare wind-chills rather than just actual temperatures). Anyway, Mt Rainier is a bit colder than Mt Washington in winter, but only because of the much greater elevation. At similar elevations, there is no contest. Here is the weather data (almost 100 years worth) for the Paradise Ranger Station, located 9000 feet below Rainier's summit: http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa6898 It is 800 feet or so lower than Mt Washington, but much warmer. However, since it is 9000 feet below Rainier's summit, it is reasonable to assume that the summit of Rainier should be much colder than down at Paradise. Although the weather data is limited, the 1970's weather data indicates that the average temperature on Rainier was 2F in January. This is 26.4F colder than the average January temperature at Paradise RS, which is 9000 feet lower. A 26.4F temperature change (which is 2.9F per thousand feet) sounds very reasonable. I would assume that the data is accurate. I would assume that you would agree that a 2.9F temperature drop per thousand feet would be reasonable?

I am the one that compiled the data for the website you are referring to. None of the data is imaginary. The idea behind the webpage was/is to gather as much information as possible on mountain top climate and weather in the United States. The data is not easy to find all in one place, other than the website and it took a lot of work to gather. The Rainier data you are referring to is from a University of Washington experiment in the 1970's. The station did not last longer than that because that's all the NPS gave permission for the experiment. I believe it lasted nine years or so. The station is not an official NWS or NOAA weather station, but unfortunately it's all the data available (or at least all of the data available that I'm aware of). Even with the limited data, Rainier is indeed much colder than Mount Washington. Mt Washington is likely windier though (no wind data is available for Rainier). As far as snowfall goes, the summit of Mt Washington is likely just as snowy as Rainier's. Most of the snow on Rainier actually falls between 4500-9000 feet elevation. Above 9000 feet the peak is often above the moist Pacific air masses the drop copious amounts of snow on the slopes of Rainier. While there is currently no weather station near the summit of Mount Rainier, there is currently one at Camp Muir. Camp Muir is at 10,110 feet elevation and the annual temperature there is 24F, about three degrees colder than that of Mt Washington. Since the summit of Mount Rainier is much colder than that of Camp Muir, it is obvious that the summit of Rainier would be much colder than Mt Washington. You can access the Camp Muir Weather Station below: https://www.nwac.us/weatherdata/campmuir/now/ Like SNOTEL sites however, these high mountain stations out West are not included in the official Nation's extremes. They are simply for scientific study purposes, to predict water runoff and availability and for recreational safety. You can access the SNOTEL data, which covers much of the western mountains below: http://www.wcc.nrcs.usda.gov/snow/ Since the primary purpose of the stations is to predict runoff though, the stations are in the mountain basins rather than on the mountain summits. Even Pikes Peak, in Colorado is significantly colder than Mount Washington, but in winter they are more evenly matched. For a bit of history, both the Mount Washington station and the Pikes Peak station were both started during the same time period. The National Weather Service was formed in 1870 and the United States Army Signal Corps were sent to both mountain locations in order to gather data. The Mount Washington station was begun in 1870 and the Pikes Peak station was started in 1873, three years later. The original purpose of both weather stations was to gather data and to see if weather could be forecasted from the top of the mountains by telegraph. Unfortunately, it was found that there was little correlation between the weather on the mountains and the surrounding country-side, so funding was cut. The Pikes Peak station was put out of commission in 1888, while after some lobbying, the Mount Washington Station was allowed to survive. During the period of record, Pikes Peak was both colder and less windy than Mount Washington. Luckily for weather watchers though, the Pikes Peak station is one again in operation, thanks to the Cog Railway. The weather data is below: http://www.cograilway.com/summit/WeatheratSummitB.htm You can obtain the data compiled by the Weather Bureau from the Signal Corps below: https://books.google.com/books?id=wVAjAQAAMAAJ&dq=coldest+temperature+recorded+on+pikes+peak&q=pikes+peak#v=onepage&q=pikes%20peak%20mount%20washington&f=false Notice that it says that Pikes Peak is definitely colder. That said, the weather on Mt Washington is impressive. It is one of, or perhaps the windiest place in the lower 48. It also has a longer period of record for mountain weather than any station I know of on earth. It is true that many western mountains are colder than Mount Washington, but Mount Washington has the most detailed record and the longest period of record, thus it can be one of the most interesting to study. In the website you are referring to, I had to gather all the data available. Unfortunately, the actual data for mountain tops is not easy to obtain. It still can be interesting and useful though. Anyway, NOAA now predicts mountain top weather on a grid and it is very interesting. If anyone is interested, it is quite interesting to compare the forecast for places like Mount Washington, Mount Rainier, and Denali (current forecasts): Mount Washington: http://forecast.weather.gov/MapClick.php?lat=44.2703&lon=-71.3033#.V9YWQ9QrLs0 http://images.summitpost.org/original/982370.JPG Mount Rainier: http://forecast.weather.gov/MapClick.php?lat=46.8529&lon=-121.7604#.V9YICNQrLs0 http://images.summitpost.org/original/982369.JPG Denali/Mt McKinley: http://forecast.weather.gov/MapClick.php?lat=63.0695&lon=-151.0074#.V9YVyNQrLs0 http://images.summitpost.org/original/982368.JPG Although it can be argued that weather forecast aren't 100% accurate, most of the time Denali and Rainier will be forecasted to be colder than Mt Washington.

Interesting, but if you compare the data for the same years for those other stations (2010-2016) Embarrass has dropped way down the list. The past few years 2010-2016 have had some warm winters (if it weren't for 2014, Embarrass would just barely beat Peters Sink). Using the NOW Data from NOAA for 2010-2016 for those stations (the same years chosen for Peters Sink), here are some differences (with the example of Embarrass shown): http://www.summitpost.org/images/medium/982247.JPG The order changes somewhat when just 2010-2016 is looked at and Peter Sinks moves up the list: Taylor Park = -9.4 Crested Butte = -8.2 Gunnison = -7.9 Embarrass, MN = -7.8 Peter Sinks = -4.7 Antero Reservoir = -4.5 Boulder Rearing Station = -4.2 In addition to Minnesota, the Wyoming stations for 2010-2016 haven't been nearly as cold as the 1981-2010 averages. Big Piney for example, has only averaged -0.5, much warmer than the 1981-2010 average of -4.0. http://www.summitpost.org/images/medium/982253.JPG Had their been a 1981-2010 average for Peter Sinks, it is possible that it also could have been colder than the 2010-2016 average.

6.8F this morning at Peters Sink: https://climate.usurf.usu.edu/PeterSinks/index.php Chilly for early September.

Thanks Chris!

Very interesting Chris. I am a mountain weather buff (I spend most of my free times in the mountains) and have long been interested in Peters Sink. There are other cold air basins (Peters Sink in unique since it has no outlet) in the Rocky Mountains that can be found either by intention or accident. I've stumbled upon many and have recorded some really cold (especially in summer temperatures) in them. For example, I have recorded a 10F in August in Quinnabaugh Meadows in the Beartooth Mountains of Montana and a 15F at Amethyst Lake in July in the Uinta Mountains of Utah, which matches the 15F record at Peters Sink. For the event at Quinnabaugh Meadows, it actually froze my 2 liter waterbottle close to solid. Sometimes in winter you can walk through these cold air sinks and valleys and notice the changes in temperatures and see the trees much more frosted with ice fog, though I've never recorded any temperatures in winter close to the ones in Peters Sink. Anyway, I would be really interested in hearing where you got the 1981-2010 PRISM dataset data for Mount Rainier, Pikes Peak, and Grand Teton. I am also interested in mountain top temperatures and have created the following webpage: http://www.summitpost.org/interesting-weather-statistics-for-us-mountain-summits/171585 I would like to get some more complete information for Rainier and Pikes Peak as well as any data for the Grand Teton or any other mountain summits.