Hi guys, I’ve seen a few topics regarding router operating temperature.
What what i’ve seen from routerboard.com and these posts is that the router is capable of operating from -30 to 70 Degrees (seems 90 is the upper limit before the router may stop functioning correctly or crash).
Although the operating temperatures have such a wide margin, are there temps where the router may start performing less optimal, or will that only really start happening in the upper end (70 + Degrees)?
The given ranges are ambient/air temperatures at which the devices have been tested and used without any effects on performance. Outside these ranges, the device performance starts to be affected. This is what the range tells you.
let me rephrase, if I understand that correctly (I am also curious about this)
“The device is guaranteed to perform the same way, within whole temperature range”
Is that right? Or are there any catches? (similar to the “waterproof” phones which must not be submerged despite IP rating)
Because I can imagine my supplier will refuse to fulfill warranty return if i give him half-melted GrooveA which was baked in oven in 69 degrees 
thanks @normis . Is it safe to assume the temp reading (although may not be 100% accurate due to the sensor you mentioned in another post about temperatures) on the Routerboards is of the CPU inside the casing?
If our ambient temperature is only ever high when its 35 Degrees, and perhaps in a rare case 40 Degrees during a heat wave, this is still well within the temperature range in order to function without temperatures impacting performance?
No, the temp reading is telling you the CPU temperature, not the ambient temperature
Vecernik, Groove should not be melted or damaged if you bake it in 69C 
it’s a normal temperature in Dubai sun, not really oven temperature.