The output data produced by numerical climate model simulations have increased greatly in complexity and size. The exploding volume of climate data is becoming a challenge for climate scientists. Our previous work, Climate Fast Input/Output (CFIO) library, implemented a two-phase I/O method to overlap I/O with computations, and achieved high throughput. In this paper, we present CFIO2, which can overlap communications with computations using Remote Direct Memory Access(RDMA) technology. We design a simple communication interactions model to implement asynchronous and concurrent data transfer. The experimental results show that CFIO2 can provide higher throughput than CFIO and can shorten the overall simulation time for climate model significantly.