Choose the type of temperature monitor for your needs. Some monitors are simple temperature indicators, while others allow for remote reading of the gauge from outside the attic. Other types contain a gauge to measure the humidity level of the attic area.
Hang the temperature monitor at a midrange level in the attic space where it is neither close to the floor of the attic nor near the roof area.
Record the temperature in the attic on a hot day in the afternoon. If the temperature is more than 50 degrees Fahrenheit more than the outside temperature, you should install more ventilation in the attic, according to the Home Energy Place website.
Record other temperatures throughout the day. For instance, take a reading at sunset, when the attic heat is greatest.
Measure the temperature of other areas of the attic to determine if attic venting is variable in different areas of the attic. These measurements will allow you to determine where more venting is needed.