Lowest Temperature on Mount Washington?

[smr260]

I've read that the US Army Signal Service weather facility that was maintained at the summit from 1870 to 1887 (year round) recorded a low temperature of -59F. Does anybody know if this is true? And if so, is there a reason this is not counted at the lowest temperature ever recorded on the summit?

(My source for this is Not Without Peril, a book by Nicholas Howe about fatalities on Mount Washington).

Thanks!
Simon

[Bill O]

I don't know the exact reason this data is not included, but my guess is that everything before a certain year (which I don't know) has been tossed out of the climate record.

I did a quick look at all the state's record max/min temperature and I couldn't find anything before 1888. I'm guessing that records were being set and measured long before that in the United States, but the process wasn't standardized at that time.

[nhwxtracker]

A lot of times weather records depend on the official calibration and usage of the instruments and whether Mt Washington was an official recording station.

The other possibility is that these are not a continuous record and when the "official" gathering of record data was conducted, these years were simply neglected or left out due to the gap in the data.

It was just recently that the all time record low for the state of NH (-47)was awarded back to Mt. Washington. It had been overlooked for many years

[treant985]

I don't know about -59, but the old 'Monthly Weather Review' magazines often listed the coldest temp reached by each state for the previous month, along with the known record for that station from that month.

The coldest I ever saw Mt. Washington listed with was -50, on January 22, 1885. Other monthly records for Mt. Washington that seemingly were set before the turn of the century (but aren't listed anywhere as 'official') include a -49 reading in March 1872, a -40 reading in November 1875, and a -47 reading in 1876. Based on my list (which admittedly is 6 years old), the listed Mt. Washington record for those three months is -38, -20, and -46, respectively.

[Bill O]

Everything pre-1888 is bunk. That is when the modern weather bureau was established. Before that there were no guidelines or standards.

That's just the way it is. -47F is the coldest official temperature Mount Washington has ever recorded.

[treant985]

Since Feb. 1948, here are the coldest minimums recorded on Mt. Washington:

month	day	year	Tmax	Tmin
1	8	1968	-19	-46
1	14	2004	-23	-45
1	15	2004	-23	-45
1	22	1976	6	-44
1	16	2004	3	-44
1	23	1976	-8	-43
2	12	1954	-10	-42
1	16	1994	-7	-42
12	30	1962	14	-41
2	12	1967	-20	-41
1	13	2004	9	-41
12	31	1962	1	-40

[Mike D]

The real impediment might simply be the inability to access the signal corps data. I heard a recent rumor that the gov't will soon be dusting off the old record books to make them available for research. I don't know exactly who has them now and who will be able to look at them, but that's the word "on the street".