In the history of satellite ice extent measurements there has only been 5 days where the extent is more than 4 standard deviations above the 1981-2010 mean.
| Year | Day of Year | Month | Day | Extent | 4 Standard Deviations For The Day of Year (According to R) |
| 2014 | 216 | 8 | 4 | 18.60657 | 18.5632626616983 |
| 2014 | 259 | 9 | 16 | 19.91462 | 19.9051244314188 |
| 2014 | 260 | 9 | 17 | 20.05401 | 19.9052905021529 |
| 2014 | 261 | 9 | 18 | 20.11297 | 19.9308463421818 |
| 2014 | 262 | 9 | 19 | 20.12703 | 19.9879316730877 |
sunshine hours 
Jeeze..
How close to 5-sigma on 9/18?
5 sigma was 20.27192 and the extent only got to 20.11297.