it does exist a plugged temperature sensor?
I need a room temperature sensor that don' work with batteries but plugghed , also if integrated in a standard device.
I use Aeotec multi-sensors. They have the option to be permanently powered by USB cord instead of batteries. If there was such a thing as a temperature sensor that was directly sticking out of the power socket I'd be worried that it would record heat generated by the power source itself or other plugs next to it.
You can try you luck with the HSM200, but mine is reporting -55.6F so mileage may vary.
The Inovelli 4-in-1 sensor can also be run on usb power instead of battery. (The usb port is under the battery)
+1 on the Aeotec Multisensors. I've been using them for a while and they are amazing. I bought them because they could be plugged in!
I make Zigbee Environment Sensor (includes Temperature reading) with DC plugged in.
nodemcu / konnected / dht22.