There are a variety of factors that impact the ability of an appliance to cool and/or maintain a specific desired temperature setting. In general, an internal temperature variance of several degrees can occur depending on how recently the compressor completed a cooling cycle, how frequently the door has been opened/closed and the ambient temperature of the room or location where the appliance is installed. If available, use a thermometer to measure the actual temperature inside the unit. Note that temperatures may vary from location to location within the interior cabinet, so taking several readings may provide the most accurate result. Also please note that air temperature inside the unit and liquid temperature of the stored contents of your refrigeration unit are not the same thing. To properly measure liquid temperature, a temperature probe or other style of liquid thermometer is needed.
Refrigeration appliances should be installed in locations where the ambient temperatures are between 50°F and 95°F. Operation outside these temperatures may result in lowered efficiency or cause other adverse effects such as difficulty maintaining temperature or the inability to reach a desired temperature. High levels of humidity in the room or location where the unit is operating can also impact the cooling performance of your appliance. If possible, try limiting the number of times the door is open and closed to minimize the amount of warm, humid air that can enter into the interior refrigeration cabinet.