The phrase "deviation range" refers to the amount or extent by which something varies or deviates from a specific standard or baseline. It describes how much something is different or off from what is expected or normal. Full definition
The gray area around the 1979 — 2000 average line shows the two standard deviation range of the data. (searcharcticscience.org)
The 1981 - 2010 average is in dark gray, and the gray area around the average line shows the standard deviation range of the data. (fm.kuac.org)
This approach yields a forecast of 5.6 million square kilometers with a one standard deviation range between 4.6 and 6.4 millions square kilometers. (searcharcticscience.org)