The electron temperature measurement by laser induced plasma spectroscopy (LIPS) in air is carried out using the relative intensity of the hydrogen line at 656.27nm to the total background-noise under the line. The theoretically established ratio is modified to include contributions from different species to the background-noise. The method was applied on plasma generated by focusing laser light at wavelength of 1064 nm onto solid aluminum target in air. Plasma emission is monitored at different laser energies in the range from 175 up to 600 mJ at different delay times from 0 to 5 s. The plasma electron temperature was measured from the slope of Saha-Boltzmann plot of relevant aluminum spectral lines. The theoretically calculated temperatures and measured temperatures are found to linearly increase with laser energy but decrease with delay time. A good agreement between the measured and predicted temperatures from the modified line to background-noise relative intensity formulae is consistently obtained.