Elucidating the role of pyrogenic carbon (C_pyr) as a global pool for CO₂ sequestration in temperate ecosystems requires information on the contribution of C_pyr to soil organic carbon (SOC) across different climatic regions. We investigated the effect of climate and basic soil properties on the accumulation of C_pyr in surface soils across the native North American prairies. Topsoil samples (0–10 cm) of 18 native grassland sites along temperature and precipitation transects from central Saskatoon, Canada, to south Texas, USA, were analyzed for benzenecarboxylic acids as molecular markers for C_pyr after nitric acid oxidation in the bulk soil (<2 mm), clay- (<2 μm) and silt-sized (2–20 μm) separates. C_pyr contributed between 4 and 18% to SOC, the major proportions of C_pyr being mostly found in the clay and silt fractions. C_pyr in soil did not correlate with basic inorganic soil properties such as pH or clay content, but it increased significantly as SOC contents increased (r² = 0.78; P < 0.001). Obviously, C_pyr co-accumulated with dead biomass. Since this accumulation depends on climate, also C_pyr contents in soil depend on climate and may be predicted by the logarithm of the ratio of mean annual temperature (MAT) to mean annual precipitation (MAP) (P < 0.05). We conclude that the natural potential of soils to sequester C_pyr reflects both, (1) higher C_pyr production at sites with high plant biomass in moist climates, and (2) lower C_pyr residence time at soils acting as a CO₂ source in warm climates.