The present work reports results of the semi-empirical determination of the spontaneous emission transition probabilities (Einstein coefficients) for Q-branch lines of Fulcher-α band system and radiative lifetimes of upper electronic-vibro-rotational (rovibronic) levels for the most important isotopologues of diatomic hydrogen. They are based on an adiabatic theoretical model and all currently available experimental data on rovibronic energy levels, ratios of the line strengths and the lifetimes. Numerical data are presented in tabular format for vibrational quantum numbers v’=0-6 and v"=0-7 (N is the quantum number of total angular momentum of the molecule excluding electron and nuclear spins). The uncertainties (one SD) of experimental and semi-empirical data are listed for each datum. Currently available results of ab initio calculations are listed and may be used for comparisons. For the d3Πu,v’=4÷6,N=1 levels of the H2 molecule the lifetimes caused by predissociation via non-adiabatic interaction with c