Why does my outdoor temperature come and go?

Outdoor Temperature Troubleshooting

Intermittent temperature readings are generally due to location of the sensor in relation to the indoor display. Following are some things to try.

RF (radio frequency) communication may come and go occasionally. This can be normal in some environments (e.g. moister climates). If transmitter signal is lost, please wait 2-4 hours for the signal to reconnect on its own.
Move the outdoor transmitter to a closer location.
Check channels on the display. The unit may be reading the sensor on a different channel. This can happen if more than one sensor is in the area and the station locks into a distant sensor first.
Reorientation of the Indoor display 90 degrees towards the outdoor transmitter may provide better reception
Fresh Batteries can often resolve connection issues
Freezer test: Confirm the station is reading the correct outdoor transmitter. Place the transmitter in the freezer for an hour and watch the temperature drop on station.

Indoor Distance Test

Complete a basic restart with the transmitter and indoor station both inside and 3-6 feet apart to establish a strong connection.
After 15 minutes if there is a reading in the outdoor temperature area, move the transmitter to another room with one wall between the transmitter and the Indoor display. Observe to see if the Temperature remains on consistently for 1-hour.
If the Temperature remains visible while in the house then it is likely a distance/resistance issue. Move the transmitter to different locations outside to find a location where the Temperature reading will hold.

Distance Considerations

Check the maximum transmitting range in open air for your unit on it's product page. Some units are 100-feet (30 meters) between the outdoor transmitter and the Indoor display. Some are over 200-feet (60 meters) open air.
Consider what is in the signal path between the Indoor display and the transmitter.
Consider the distance the Indoor display is located away from other electronics in the home.

Resistance Considerations

Obstacles such as walls, windows, stucco, concrete, and large metal objects can reduce the range.
When considering the distance between the transmitter and the Indoor display cut that distance in half for each wall, window, tree, bush or other obstruction in the signal path.
Closer is better.
Do not mount the transmitter on a metal fence. This significantly reduces the effective range.

Interference Considerations/Sources of Interference

Consider items in the signal path between the transmitter and the Indoor display.
Sometime a simple relocation of the transmitter or the Indoor station will correct the interference issue.
Windows can reflect the radio signal.
Metal will absorb the RF (radio frequency) signal.
Stucco is held to the wall by a metal mesh, thereby creating interference.
Transmitting antennas (ham radio, emergency dispatch center, airports, military base etc.)
Electrical wires (utilities, cable etc.)
Vegetation is full of moisture and reduces signal.
Earth: Trying to receive a signal through a hill is difficult.