The climate data for the South Pole, as reported by Wikipedia, indicates that the average annual precipitation there is 2.3 mm, with an average of 1.6 precipitation days and 203.0 “snowy days”.
How is the word “snowy day” defined here? I thought it would be “a day where there is precipitation in the form of snow”, but doesn’t make light in sense of the precipitation statistics. It also can’t be “a day when there is snow on the ground”, because then I would expect the number of snowy days to always be 365 (in a non-leap year). Is it possibly “a day when there is snow in the air”, which admits the possibility of snow from the ground being blown up by the wind? If so, how does one distinguish (for the purposes of measurement) between precipitated snow and blown-up snow? I mean, presumably they have some sort of device on or near the ground that collects snow. Is there some way of constructing such a device such that it collects only that snow that falls directly from the clouds, as opposed to ground snow that is returning to the earth after being blown up by the wind? How would that work on days when it is both windy and snowing?
The data file cited by Wikipedia has a separate category for “number of days with blowing snow”, though, and the numbers are different than those in the Wikipedia article. The numbers that Wikipedia is using are the data for “number of days with snow/hail.”
If I had to guess, I’d say that there are a lot of days with only trace amounts of new snowfall, but relatively few where there is more than 0.1 mm of precipitation (which I suspect is measured in liquid water equivalent, so it’s not as small as it sounds.) To back this up, look at Table 9 in the above link: the median daily snowfall in all months of the year is “Trace”, as are the 25th & 75th percentiles. (The median is the amount of snowfall for which half of the days have less, and half have more; 25th percentile is the amount for which only one-quarter of the days have less.)