For the most accurate readings, install outdoor thermometers several feet above the ground in a north-facing location. Place the thermometer in a shaded area with good airflow and protection from precipitation.
To obtain an accurate temperature reading, it is important to reduce the influence of factors that could provide inaccurate results. To minimize the effects of ground temperature, install the thermometer at a height of 4 to 6 feet. If possible, choose a location at least 100 feet away from concrete, asphalt and other paved surfaces, as they absorb and radiate a lot of heat that can cause inaccurate readings.
Select a spot where the thermometer is always in shade. Direct sunlight can affect the accuracy of the thermometer by heating it up, resulting in the thermometer reporting a temperature that is higher than the surrounding air. A specially constructed weather station shelter is ideal; otherwise, install the thermometer in a north-facing location in an area that is out of direct sunlight. Precipitation also affects the accuracy of the reading, so choose a protected area where the thermometer can be kept dry. Ensure the protected area has good ventilation, as adequate airflow is important for the thermometer to accurately reflect the local conditions.