A 3D heterogeneous processor (commonly termed as 3DHP) integrates multiple processor (such as CPU/GPU) and DRAM dies, interconnected vertically by a massive number of Through-Silicon Vias (TSVs). The 3DHP is expected to address the limited bandwidth, high latency and energy consumption of off-chip DRAM. However, spatial and temporal variability due to hotspots in on-chip thermal gradient may result in wide bit error variation in DRAM dies. This work proposes a novel adaptive multi-path BCH decoder to efficiently address this issue. Instead of having a static BCH decoder designed from the worst-case bit error probability analysis, the proposed adaptive multi-path BCH decoder offers multiple decoding paths with varying target number of error bits to correct, which is estimated from the thermal gradient data generated by on-chip temperature sensors. Thus, it minimizes the overall decoding latency adaptively. The proposed approach has been verified by implementing an adaptive 4-path BCH decoder in FPGA hardware. A series of decoding performance evaluation data has been generated to demonstrate the efficiency of the proposed design.