A sensor node comprising: a first to nth (n is an integer equal to or greater than two) environmental sensors which are configured to acquire ambient environmental information; a transmitter that is configured to regularly issue ambient environmental information acquired by at least one of the second to nth environmental sensors at a predetermined cycle and is configured to irregularly issue ambient environmental information acquired by the first environmental sensor and ambient environmental information acquired by at least one of the second to nth environmental sensors; a detector that is configured to detect a change value of ambient environmental information acquired by the first environmental sensor greater than a first threshold value; and a transmission interval controller that is configured to control a timing at which the transmitter regularly and irregularly issues the ambient environmental information, wherein power is constantly supplied from a power storage to the first environmental sensor, the transmission interval controller, and the detector when storage capacitance of the power storage is equal to or greater than a predetermined level, and wherein the transmission interval controller is configured to: control a timing of sensing by the second to nth environmental sensor within the predetermined cycle and a timing of issuing by the transmitter to cause the transmitter to perform the regular issuance; and control a timing of sensing by the second to nth environmental sensor and a timing of issuing by the transmitter to cause the transmitter to perform the irregular issuance, according to a predetermined condition, when the change value greater than the first threshold value is detected by the detector. a first to nth (n is an integer equal to or greater than two) environmental sensors which are configured to acquire ambient environmental information; a transmitter that is configured to regularly issue ambient environmental information acquired by at least one of the second to nth environmental sensors at a predetermined cycle and is configured to irregularly issue ambient environmental information acquired by the first environmental sensor and ambient environmental information acquired by at least one of the second to nth environmental sensors; a detector that is configured to detect a change value of ambient environmental information acquired by the first environmental sensor greater than a first threshold value; and a transmission interval controller that is configured to control a timing at which the transmitter regularly and irregularly issues the ambient environmental information, wherein power is constantly supplied from a power storage to the first environmental sensor, the transmission interval controller, and the detector when storage capacitance of the power storage is equal to or greater than a predetermined level, and wherein the transmission interval controller is configured to: control a timing of sensing by the second to nth environmental sensor within the predetermined cycle and a timing of issuing by the transmitter to cause the transmitter to perform the regular issuance; and control a timing of sensing by the second to nth environmental sensor and a timing of issuing by the transmitter to cause the transmitter to perform the irregular issuance, according to a predetermined condition, when the change value greater than the first threshold value is detected by the detector. control a timing of sensing by the second to nth environmental sensor within the predetermined cycle and a timing of issuing by the transmitter to cause the transmitter to perform the regular issuance; and control a timing of sensing by the second to nth environmental sensor and a timing of issuing by the transmitter to cause the transmitter to perform the irregular issuance, according to a predetermined condition, when the change value greater than the first threshold value is detected by the detector.