Interesting Weather Statistics for US Mountain Summits : Facts & Information : SummitPost

Introduction

I thought these statistics could be interesting for climbers. Here are some climate statistics for several mountains in the United States (arranged from coldest to warmest for lack of any better way to do it).

There are only a few mountain tops with weather statistics and most of them are located in the Eastern USA. There have been at one time several peaks in the Western US with weather data, but none of the weather stations below are currently operating, though the data is still available if you dig hard enough for it.

Temperatures

Denali is not surprisingly by far the coldest of all the mountain tops in the United States. In fact, during summer Denali is still colder than any location in the lower 48 is during winter. It is also the coldest place in the world outside Antarctica.

Obviously Mount Rainier is by far the coldest of all these mountain tops in the lower 48. Interestingly though, Mount Rainier is about the same temperature in winter as Pikes Peak or Mount Washington. It is however, much colder in summer.

Pikes Peak is much farther south than Mount Rainier, but I assume that the Pacific air on Mount Rainier keeps the mountain “milder”, temperature wise in winter than it would otherwise be. Mount Rainier is by far a much wetter and stormier mountain (precipitation wise) than Pikes Peak. No precipitation values that I know of are available for Mount Rainier summit area, though at 5550 feet at Paradise Ranger Station, an average of 117 inches of precipitation falls. Mount Washington averages near 99 inches, but the summers are too “warm” for glaciers to form.

White Mountain 2 in the White Mountains in California is almost as cold as Mount Washington. However, it is “warmer” in winter and cooler in the summer than Mount Washington. Since White Mountain 2 is actually over 1500 feet lower than White Mountain itself, it is probable that the summit of White Mountain is colder than Mount Washington.

Mount Mitchell is much warmer than these other peaks, but interestingly the all time record low is almost as cold as the other locations (except Denali). Mount Washington has recorded temperatures down to -47, Pikes Peak down to -39, Mount Mansfield down to -39, Mount Rainier down to -36, and White Mountain 2 down to -35. All these mountains only have a span of 13 degrees between their all time record lows. One old minimum gage thermometer left on the summit of Denali plunged to -95. Since the thermometer sat on the ground, it isn't official, but temperatures have been thought to drop at least to -77. In the summer, it is likely that the summit never reaches freezing.

Records for Mount Mitchell, Mount Washington, and Mount Mansfield span many decades, while the other mountains have record for much less time. The longest period for a Western US mountain belongs to White Mountain 2 where data was collected for 25 years.

Annual Temperatures:

PEAK	STATE	ANNUAL
Denali	AK	-28.0
Mount Rainier	WA	11.9
Pikes Peak	CO	18.8
Uinta Mountains	UT	20.0
Mount Washington	NH	27.2
White Mountain 2	CA	27.5
Mount Mansfield	VT	34.3
Mauna Kea	HI	36.3
Mount Mitchell	NC	44.6
Mauna Loa Slope	HI	44.7

Wind Speed

Unfortunately, wind speed data is hard to obtain for most of these mountains. Of all these mountains, Mount Washington is the only one with long term wind data.

Other than wind data for Mount Washington, I could also find it for Pikes Peak and Longs Peak in Colorado. Longs Peak and Mount Washington are about the same in wind speed and both are significantly windier than Pikes Peak. Mount Washington had a record wind gust of 231 mph in April 1934. Longs Peak had a record wind gust of 201 mph in 1981, but the station only lasted a short time. During the period of record, Pikes Peak had an estimated maximum wind gust of 150 mph, but the anemometer blew away 112 mph.

Unfortunately, Long Peak doesn’t have any temperature data compiled; only wind, so wind chills are hard to compare. More than likely, Long Peak is similar in temperatures to Pikes Peak, but a few degrees colder.

It seems no wind data is available for the other summits listed below. It would be interesting to see how windy the high peaks in the Cascades or California are compared with the Rockies or Appalachians.

Peak	Average Wind Speed
Mount Washington	35.3
Longs Peak	34.3
Pikes Peak	21.2

Denali, Alaska (20,320 feet)

Month	Ave High	Ave Low	Rec High	Rec Low
JAN	-33	-43	?	-77
JUL	-3	-13	30	-23

Source: Statistics are from the book Skywatch West by Richard A Keen, page 247 and are based on weather balloon data. Unfortunately only January and July info is available. The -23F figure for July comes from the Weather Station located at 19,000 feet.

Mount Rainier, Washington (14,411 feet)

MONTH	HIGH	LOW
JAN	7	-3
FEB	9	-2
MAR	11	-2
APR	17	2
MAY	22	6
JUN	26	10
JUL	33	15
AUG	32	14
SEP	28	12
OCT	20	7
NOV	14	2
DEC	8	-2

Source: National Park Service, courtesy of University of Washington.

Period of Record: Unknown; 1970's.

Pikes Peak, Colorado (14,115 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip Notes
Jan	8	-4	?	?	8-10 days of snow
Feb	11	-3	?	?	9-10 days of snow
Mar	14	-1	?	?	9-11 days of snow
Apr	20	5	?	?	12-13 days of snow
May	28	14	?	?	17 days of snow; some rain
Jun	39	25	?	?	9 days of snow; 9 days of hail
Jul	48	34	64	?	7 days of snow; 15 days of hail or rain
Aug	48	33	?	?	28 days of snow, hail, or rain
Sep	39	24	?	?	10 days of snow; 5 days of hail or rain
Oct	28	14	?	?	8-9 days of snow
Nov	16	4	?	-36	9-10 days of snow
Dec	11	-3	?	-39	9-12 days of snow

Other info: Pikes Peak averages 29.7 inches of precipitation and 553 inches of snow per year.

Source: Uinted States Army Signal Corps; courtesy of Larry Dunn. Annual "other info" stats above are from the book Skywatch West by Richard A Keen, page 248.

Period of Record: 1873-1888 and sporatically in recent years. Daily highs and lows are currently being taken again on the site below:

Pikes Peak Summit Weather

Uinta Mountains, Utah (13,123 feet)

MONTH	HIGH	LOW
JAN	11	-4
FEB	13	-2
MAR	16	1
APR	24	8
MAY	32	15
JUN	42	22
JUL	52	29
AUG	50	28
SEP	42	21
OCT	31	12
NOV	19	5
DEC	14	0

Source: Interpolation from Mesowest Data, Chepeta Station (CHPU1).

Period of Record: 1998-Present

Mount Washington, New Hampshire (6288 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip (in)	Snowfall (in)
Jan	14	-4	47	-47	8.52	50.4
Feb	15	-2	43	-46	7.33	48.2
Mar	21	6	54	-38	9.42	51
Apr	29	16	60	-20	8.43	40.8
May	42	30	66	-2	8.21	11.3
Jun	50	39	72	8	8.36	1.2
Jul	54	43	71	24	8.02	0
Aug	53	42	72	20	8.08	0.3
Sep	46	35	69	9	8.55	2.2
Oct	36	24	59	-5	7.66	14
Nov	28	14	52	-20	10.49	40.4
Dec	19	2	47	-46	8.84	55.0

Source: National Weather Service database (National Climatic Data Center).

Period of Record: 1870-1892 and 1932-Present

White Mountain 2, California (12,470 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip (in)	Snowfall (in)
Jan	23	7	47	-25	2.00	20.2
Feb	23	7	52	-21	1.70	19.5
Mar	24	7	46	-35	2.17	19.5
Apr	28	10	50	-30	1.88	20.8
May	36	19	59	-15	1.98	21.5
Jun	46	29	66	2	0.82	7.0
Jul	54	36	72	12	1.09	1.3
Aug	53	35	73	13	1.11	1.0
Sep	48	30	61	-5	0.87	3.5
Oct	40	23	69	-20	1.02	10.9
Nov	31	15	50	-28	1.22	13.1
Dec	25	10	48	-30	2.60	20.3

Source: National Weather Service database (National Climatic Data Center).

Period of Record: 1955-1980

Mount Mansfield, Vermont (4393 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip (in)	Snowfall (in)
Jan	17	1	50	-39	5.94	43.1
Feb	19	3	51	-36	4.49	31.7
Mar	27	12	64	-29	5.85	35.3
Apr	39	24	74	-13	6.28	21.5
May	53	37	79	5	6.16	3.8
Jun	62	46	84	20	6.88	0.2
Jul	65	51	82	24	7.47	0.0
Aug	64	50	79	25	8.02	0.0
Sep	56	42	79	16	7.55	0.4
Oct	45	30	71	-5	6.39	7.6
Nov	33	19	63	-15	7.40	32.4
Dec	22	7	60	-40	6.37	43.1

Source: National Weather Service database (National Climatic Data Center).

Period of Record: 1954-Present

Mauna Kea, Hawaii (13,796 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip (in)
Jan	37	25	55	19 (9?)	1.4
Feb	39	25	56	12	1.4
Mar	41	25	54	18	1.7
Apr	42	27	55	18	1.4
May	48	29	59	12	1.1
Jun	50	30	58	23	0.8
Jul	51	31	61	22	1.1
Aug	52	30	57	17	1.3
Sep	43	32	60	23	0.9
Oct	50	31	59	20	1.2
Nov	40	28	54	20	1.5
Dec	38	26	55	17	1.7

Source: Both the Western Regional Climate Center and the Hawaii Atlas have weather data for Mauna Kea. Unfortunately, the data averages from either source does not match well. The data from the atlas was here used because it is the most complete. Aveage precip values are higher and low temperatures lower than the WRCC averages, which only includes data from a short time span. The all time records were taken from the WRCC, though a figure of an all time record low of 9 in January has been reported by other sources.

Period of Record: 1972-1982; sporatic

Mount Mitchell, North Carolina (6634 feet)

Month	Ave High	Ave Low	Rec High	Rec Low	Precip (in)
Jan	34	17	61	-34	7.00
Feb	36	19	62	-23	5.41
Mar	43	25	65	-15	7.93
Apr	51	33	73	-1	5.34
May	58	42	78	11	5.93
Jun	65	49	78	27	5.57
Jul	68	53	80	38	6.70
Aug	68	52	81	34	7.39
Sep	63	47	78	24	4.87
Oct	56	38	72	5	5.10
Nov	47	29	66	-21	6.36
Dec	39	21	60	-22	6.90

Source: National Weather Service database (National Climatic Data Center).
Period of Record: 1953-1965; 1985 and 1988-Present

Mauna Loa Observatory, Hawaii (11,140 feet)

MONTH	AVE HIGH	AVE LOW	REC HIGH	REC LOW	AVE PRECIP (in)
JAN	50	33	67	19	2.48
FEB	50	33	64	18	1.51
MAR	50	33	65	20	1.75
APR	52	35	67	24	1.33
MAY	54	37	68	27	1.00
JUN	57	39	71	28	0.51
JUL	56	39	70	26	1.16
AUG	56	39	68	28	1.50
SEP	56	38	67	29	1.36
OCT	55	38	66	27	1.16
NOV	53	36	65	25	1.78
DEC	51	34	67	22	2.01

Source: National Weather Service database (National Climatic Data Center).

Period of record: 1955-Present

Images