A temperature monitoring system includes a thermometer and a first communication device. The thermometer counts a monitoring time, executes a measuring procedure to acquire a first temperature value and a second temperature value to determine whether to wirelessly broadcast a temperature information signal, and executes a time interval producing procedure after the measuring procedure to determine a time interval and to determine whether the measuring procedure is terminated. The first communication device receives the temperature information signal from the thermometer. The user may remotely monitor the temperature of a monitored object through the first communication device.