Do you get standard deviations when you watch the summary today's weather on the news? I think the statistical detail was appropriate.
If you are seriously proposing that standard deviation makes an average 8.6 degrees above normal insignificant then you are going to have to present some pretty compelling evidence. NOAA do generally know how to do some basic math.
A standard deviation of greater than 4.48 degrees would make 8.6 degrees above average insignificant, assuming a normal distribution (alpha = 0.05, two-sided Z-test).
I do understand what standard deviation is, and I do understand that it is possible that a 8.6 degrees difference would be significant. What I meant was that NOAA wouldn't be highlighting this unless it was.
Anyway, it's public data, and we can settle this pretty easily, right?
I other words, (again, if your calculations are correct) if this were a typical HN discussion about A/B testing a conversion goal, we'd all be ridiculing anybody who suggested a result almost 3 standard deviations from the mean _wasn't_ "statistically significant", yet climate change (sceptics|denialists) will no doubt _still_ argue the relevance of this…
The bigger problem (as others have alluded to) is that we don't really know what the tail of the distribution looks like. There's no obvious reason to think it's gaussian.
If the standard deviation is 10, then 8.6 degrees above the mean is insignificant. Providing a number like 8.6 without the s.d. is presenting zero evidence. That's like page two of my statistics textbook.
I was replying to the parent comment, not the story, and the claim that we could somehow determine the significance of 8.6 without knowing more. As for press releases, "It was hot" is probably a sufficient level of detail for most people. :)
If you are seriously proposing that standard deviation makes an average 8.6 degrees above normal insignificant then you are going to have to present some pretty compelling evidence. NOAA do generally know how to do some basic math.