Record Low

[treant985]

Maybe this has been discussed before, but does anyone know what is considered Mt. Washington's coldest recorded temperature? I don't necessarily mean what does MWO consider their coldest reading to have been.

I ask because I noticed a while back that -50F had been recorded on Mt. Washington by the Signal Service on Jan 22, 1885. It was noted in their monthly report and also mentioned in the 'Monthly Weather Review,' which is a major source of weather data for the 1800s. I just noticed that Mt. Washington's page on wikipedia has been changed to include the following paragraph, which doesn't cite its source:

"For many years, the record low temperature was thought to be −47 °F (−44 °C) occurring on January 29, 1934, but upon the first in-depth examination of the data from the 1800s at NOAA's National Climatic Data Center in Asheville, North Carolina, a new record low was discovered. Mount Washington's official record low of −50 °F (−46 °C) was recorded on January 22, 1885. However, there is also hand-written evidence to suggest that an unofficial low of −59 °F (−51 °C) occurred on January 5, 1871."

I'm not sure about that -59F on 1/5/1871, as I can't find any records of it; but it does seem that the -50F on 1/22/1885 would be legitimate.

As I hinted above, MWO may not consider that to be their coldest reading on the mountain--but does the NOAA or National Climatic Data Center consider it to be so?

[hobbes]

See http://www.mountwashington.org/weather/normals.php

[treant985]

See http://www.mountwashington.org/weather/normals.php

Did you even bother to read my entire post?

[Bill O]

Isn't there some cutoff point in the late 1800's for weather records in the US? Maybe that's why your -50F isn't listed in any common sources.

[treant985]

I'm not aware of any official cut-offs, although I know that I personally consider most records from pre-1900 to be suspect. From going through dozens of those old weather review books, I think it was way too easy back then for someone to say say 'well, I got 10" of rain last week' and for it to get printed somewhere as 'well, he got 10" of rain in one day last week' and so on, until it's written down as an all-time record with no verification at all.

But temps tend to be my one exception to that 'rule.' Granted, thermometers weren't as accurate and standardized as today's, but I think they're much less susceptible to exaggeration or miscommunications or reading errors.

Anecdotally, I do know that Minneapolis/St. Paul considers their all-time record low to be -41 in Jan 1888. Also, the great cold wave of 1899 set records that still stand, but I think that, by 1899, things were well on their way to being standardized, making those readings credible.

[mtruman]

I did some quick research on this and was amazed to see how many seemingly reliable sources have different figures for this. I found anything between -45 and -50 (with about 5 different values in that range). You'd think that this would be a reasonably consistently record.

I found something else interesting however that should appeal to those who like extreme weather. There's a book titled "Extreme Weather: A Guide & Record Book" with text available on Google BookSearch (http://books.google.com/books?id=SV2...Wt4TM#PPA45,M1

I expected to find some figure for the MW record, but it wasn't there. There is an interesting quote on page 51 which cites MW as the coldest location year round in the US outside Alaska with an annual average of 27.2. They go on to say: "Of course, nobody actually lives year round on the summit of Mount Washington..." Guess they forgot the observatory staff.

[treant985]

I did some quick research on this and was amazed to see how many seemingly reliable sources have different figures for this. I found anything between -45 and -50 (with about 5 different values in that range). You'd think that this would be a reasonably consistently record.

I found something else interesting however that should appeal to those who like extreme weather. There's a book titled "Extreme Weather: A Guide & Record Book" with text available on Google BookSearch (http://books.google.com/books?id=SV2...Wt4TM#PPA45,M1

I expected to find some figure for the MW record, but it wasn't there. There is an interesting quote on page 51 which cites MW as the coldest location year round in the US outside Alaska with an annual average of 27.2. They go on to say: "Of course, nobody actually lives year round on the summit of Mount Washington..." Guess they forgot the observatory staff.

I have that book (the updated 2007 version), and it's probably my most-used source for basic weather records. It's got a good mix of charts, maps, data tables, and reliable (as much as weather records can get) info for most of the USA, as well as interesting places in other countries. I'd really recommend it.

I also saw the part about no one living year-round on the summit. I think he meant that no one person is there pretty much year-round, ie no denizens.

[treant985]

By the way, that extreme weather guide book does have a list of each state's coldest recorded temp. He says -47 for NH at MWO on 1/31/1934.

But having checked out a lot of his sources in-depth, I believe that the majority of his data were from the NCDC in Asheville--and I don't think they've entered those 1800s records from Mt. Washington into their big database of records.

The NOAA has a page that lists each state's coldest & hottest temp for each month of the year, but it's way out-dated. I don't know the url, but I did save a pdf copy. It lists -47 for MWO, as well. But again, remember that these -50F readings were apparently 'just discovered' by the NCDC. So these older publications wouldn't have them in there even if the NOAA accepted the -50F or -59F readings.

[mtruman]

By the way, that extreme weather guide book does have a list of each state's coldest recorded temp. He says -47 for NH at MWO on 1/31/1934.

That's what I was looking for but didn't find it. In the end, -47 or -50something are really @$%^ cold - but then, it's all about the records.

As to the "residents on the summit" I think that the observatory staff should get credit for their winter stays - denizens or not. Quite a place to live if only for short stints. Then again, what about the cats? Do they count as year round residents?

[Bill O]

That's a great book. I'm always looking through mine.

Its easy to forget that when it comes to record cold, mountain tops are usually never the winners. If Mount Washington can get to -47F then some high mountain sinks in NH and VT have been colder.