We consider the effects of weak gravitational lensing on observations of 196 spectroscopically confirmed Type Ia Supernovae (SNe Ia) from years 1 to 3 of the Dark Energy Survey (DES). We simultaneously measure both the angular correlation function and the non-Gaussian skewness caused by weak lensing. This approach has the advantage of being insensitive to the intrinsic dispersion of SNe Ia magnitudes. We model the amplitude of both effects as a function of σ8, and find σ8 =1.2 $^{+0.9}_{-0.8}$ . We also apply our method to a subsample of 488 SNe from the Joint Light-curve Analysis (JLA; chosen to match the redshift range we use for this work), and find σ8 =0.8 $^{+1.1}_{-0.7}$ . The comparable uncertainty in σ8 between DES─SN and the larger number of SNe from JLA highlights the benefits of homogeneity of the DES─SN sample, and improvements in the calibration and data analysis....
