ETI
An analogue room thermometer from ETI, the British thermometer maker: a plain dial that reads the tent's temperature with no batteries.
In StockETI
£4.46
About ETI
Using it
Hang it at canopy height, out of the direct light. For humidity as well, and for a record of what happens at night, see the digital meters.
Related
Digital and Bluetooth hygrometers are under Hygrometers.