The meterologist-skier running a site in the upper midwest once told me
that snow temp follows air temp by about two hours. For planning in
advance, I use the NWS hourlies for the location or nearby where the
lat-long is known, or the SNOTEL data reports for a closeby location.
The latter go back a week.

Gene

On Thu, 24 Jan 2013 09:20:16 -0000
"Neil" wrote:

Dear All,
How useful a guide is air temperature for waxes. I was out in +6 but
a blue. I should point out that I tend not to pack a thermometer when
ski touring. wax -6 to 0 worked fine.