We are looking for the average temperature where you will be hunting/shooting in Degrees Fahrenheit (°F). Your turret will remain accurate 20°F above and below the entered value (i.e. you have a 40°F window to work with). In terms of environmental factors, altitude and temperature are going to have the largest impact on the accuracy of your turret. Therefore, if you plan to use your firearm in locations with large variances in temperature or across multiple seasons, we recommend purchasing multiple turrets for warm and cold weather to ensure turret accuracy.