Temperature and absolute concentrations of OH and H are measured by UV Rayleigh scattering, Laser-Induced Fluorescence (LIF), and Two-Photon Absorption LIF (TALIF), respectively, in Ar-based mixtures (Ar: H2= 100: 2 and Ar: O2: H2= 80: 20: 2) at P= 40 torr and T0= 300 K. Each mixture is excited by a 50-pulse burst of a repetitive nanosecond pulse filament discharge, operated at 100 kHz pulse repetition rate and 5 Hz burst repetition rate. Onedimensional radial distributions of temperature and species concentrations across the filament during and after the discharge burst are obtained from Rayleigh scattering and fluorescent images of the laser beam, taken by an intensified charge-coupled device (ICCD) camera. Both temperature and species concentration profiles are found to expand with time in both mixtures, with peak values of Tpeak≈ 1200 K and [H] peak≈ 4.0· 1015 cm-3 in the Ar: H2= 100: 2 mixture, and Tpeak≈ 1200 K,[H] peak≈ 6.0· 1015 cm-3, and [OH] peak≈ 1.0· 1015 cm-3 in the Ar: O2: H2= 80: 20: 2 mixture. H atom radial profile develops a local minimum on the discharge centerline in both mixtures, but is much more pronounced in the Ar: H2= 100: 2 mixture. In the Ar: O2: H2= 80: 20: 2 mixture, secondary maxima in OH distributions are detected near the periphery of the filament after a few tens of discharge pulses. Experimental results from the Ar: O2: H2= 80: 20: 2 mixture are compared with predictions of a plasma-assisted combustion chemistry model. The model reproduces trends in time evolution of radial distributions of temperature, as well as OH and H concentrations. Based on rate of species production analysis, the secondary peaks in OH radial distributions are caused by radial diffusion of H atoms from the central region of the discharge filament, with subsequent formation of HO2 and OH via reactions H+ O2+ M→ HO2+ M and H+ HO2→ OH+ OH in the low-temperature peripheral regions. The results demonstrate significant potential of the present approach for quantitative, time-and spatially-resolved studies of coupled radical reaction kinetics and diffusion over a wide range of temperatures, pressures, and mixture compositions.