My temperature readings actually +2C higher when it should be. Is it possible to add this difference on blynk app? Or Needs changing the code?
Rekards, Kes.
DHT11 has poor accuracy, nothing new. Just change your code, add -2 to temp reading and you will be fine.
@m0pkz you might want to do nothing at all as temperature is “subjective”, not technically but hopefully you know what I mean.
We have expensive aircon units here with temperature gauges that show 25 degrees but the actual temperature in the room is more like 21 degrees. So I know from experience that if I want 25 degrees in the room I need to set the aircon to around 29 degrees.
You might want to switch to DS18B20’s.
Is it possible on the blynk app? or the code only the way?
It has nothing to do with Blynk app, so you will have to change the code. It’s not complicated at all, post your code and we will show you what to do.
Code only but you you can use slider and step widgets etc to “calibrate”.
The prob is I didn’t got the code anymore 
not sure if i can read from Arduino nano…it’s not very dificult code but…it would be easier for me to change via blynk…how to use slider and step widgets to calibrate?
or is it possible add -2 in lable value?
There is NO calibration. The DHT11 only has a ±2°C accuracy range… adjust for 2° either way and it is likely to be off in the other direction next time… 