14er weather and climate

[Scott P]

I’m posting this for anyone interested in Colorado mountain climate, weather, and statistics. I hope it’s interesting to some. There was a recent thread in the FB group about weather conditions in a certain month, but no real data. Here is some information for some real data in the Colorado mountains, including the 14ers.


Random data/trivia:


Snow depth in the Colorado mountains usually peaks in April with March through May having the deepest snows of the season. Snow depth can peak anytime early March through late May, but early to late April is most common.


The snowiest month varies widely throughout the Colorado mountains. In the Front Range cities, for example, March tends to be the snowiest month, but as you go higher in the mountains of the Front Range, April or even May are the months with the highest snowfall. This is not true throughout Colorado though. In many mountain areas in Northwest Colorado, such as the Park Range, December and January are the snowiest months and snowfall drops off significantly in March and April.


The Park Range is the snowiest area in Colorado. Some sources might list the area around Wolf Creek Pass in the San Juans as being the snowiest, but that’s only because SNOTELs aren’t official weather stations since most of the data they collect is related to snowpack and because they aren’t in populated areas. SNOTELs show that the Park Range is significantly snowier than the area around the San Juans and is probably the only place in Colorado where annual snowfall averages around 500” a year.


The least snowy high mountain areas in Colorado are the Mosquito Range, southern Sawatch, and much of the Sangre de Cristos.


Pikes Peak, Mount Blue Sky, and Longs Peak are the only 14ers with weather data available. Weather/Climate Data for Pikes Peak is below:


https://www.summitpost.org/pikes-peak-c ... ics/337874


Mount Blue Sky also has some weather data available, but in annual form rather than by month.


Data comparing some 14er summits in comparison to other mountains in the USA is below:


https://www.summitpost.org/interesting- ... its/171585


The weather station on Longs Peak mostly only measured windspeed and was only on the summit less than a year (1981). Even though the weather station lasted last than a year, it recorded a 201 mph windspeed, one of the strongest windspeeds ever recorded in North America. Had the weather station lasted longer, it likely would have even recorded higher speeds. By way of comparison, a Category 5 Hurricane is defined by winds of at least 157 mph. Longs Peak is probably one of the windiest locations in North America during winter.


The coldest temperature ever recorded at a weather station on a 14er was -40F (or C!) and it likely doesn’t get much colder than that on any of the 14ers. The reason the mountain tops don’t have as cold of extremes (the coldest temperature recorded in Colorado was -61 at Maybell at only 5920 feet) is because the mountain tops are usually windy and aren’t subject to cold air pooling which affects the basins and valley bottoms. The average temperatures are lowest on the highest mountain peaks, but the extremes are not. Windchills are almost always lower on the highest mountains though and are extreme for much of the year.


The warmest temperature ever recorded on a 14er weather station was 65F. It was 105 in Denver that day. Even if they don’t have weather stations, it is very likely that a Colorado 14er will ever get much warmer than 65F.


The mountain summits don’t have nearly the difference between night and day temperatures that the lower elevations do and their annual range is much smaller as well. There also is a lot more seasonal lag in temperatures the higher you go. For example, on Pikes Peak May and October have almost the exact average temperatures. In Colorado Springs, May is significantly warmer than October.


Snow can and does fall on the high mountains year round. While the weather station was operational at Pikes Peak, snow fell on all months every year except for one warm August in a very dry summer. Snow has fallen on occasion in Colorado as low as 8000 feet in July and August and once in July 1872, it even fell in Denver. This would be extremely rare though. The last time I know of where it snowed below 8000 feet in Colorado during July was 1993 where some of the mountain towns cancelled their 4th of July fireworks displays due to snowfall.


The wettest and driest months in Colorado varies widely depending on where you are. In the Front Range the driest month on average is September. In much of western Colorado, September is the wettest month, including in parts of the San Juans. Thunderstorm activity peaks in July and August throughout Colorado, but starts earlier and ends earlier in the Front Range and begins and ends later in the San Juans. Early to mid-September is very much still thunderstorm season in the San Juans, while June and often early July tend to be much drier.


TMI perhaps, but here are the coldest nights I have spent and recorded the temperatures in the region's mountains:


https://www.summitpost.org/overnight-te ... ies/186172

[Jorts]

Quality weather review Scott.

I’ve always found it interesting how different ranges and resorts are favored by different storm flows. Like the Tenmile wins out on NW flow, Vail on westerly, and the SJs on SW. Steamboat does well on NW and SW flow. Ask any seasoned ski patroller which flow hammers their resort most and they can even give you a narrower range on the compass.

[two lunches]

cool post, scott! thanks

[rijaca]

Good info!

The last time I know of where it snowed below 8000 feet in Colorado during July was 1993 where some of the mountain towns cancelled their 4th of July fireworks displays due to snowfall.

My notes from July 4, 1993: Hike Mt Hope with Mark B. Snowstorm with fresh snow on the ground.

[Tony1]

The least snowy high mountain areas in Colorado are the Mosquito Range, southern Sawatch, and much of the Sangre de Cristos.

A good example of why - though this may sound funny to say about a place that sits at 10,200 feet - Leadville is the tip of the banana belt.

[Scott P]

The least snowy high mountain areas in Colorado are the Mosquito Range, southern Sawatch, and much of the Sangre de Cristos.

A good example of why - though this may sound funny to say about a place that sits at 10,200 feet - Leadville is the tip of the banana belt.

Yes. Rain/snow shadow effect. The areas just south of Leadville and Fairplay are even drier.

Precipitation wise, the area south of Fairplay is drier than Tucson Arizona, even though it's at high elevation and much colder.

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