That is the way the LM34 is when running on 5 volts. Figure the steps in 8 bit and all that.

If you want a 1 degree resolution set up the VREF and have the reference voltage at 3.3 volts.

Then in place of multiplying by 2
you would use
ADC_VAR * 4 / 3

At least that works for me

Glad you got it going.