The seasons play an important role in Anton Chekhov's story. The summer setting in Yalta where Dmitry and Anna meet is especially relevant for the heat of their passion. Dmitry is hot blooded in his libido, but cool in his emotional detachment—this is far from his first affair. Anna is warmer emotionally, and taking this plunge is new for her. The affair heats up over the summer, and it seems that it will die off.
The seasonal metaphor is not mechanically applied, however, even as the author does not tie the plot up neatly. The love continues to grow. We might say that the seeds planted are growing to maturity. The two people's perspectives approach each other until they arrive at a certain equality or harmony. We see that the mature fruit of this combined love will be carried forward, somehow.
Author's often use weather or seasons to symbolize the dominant themes of their work. It is often the case that a passionate relationship will fade over time, and what seemed exciting and new at first becomes commonplace. Thats the cooling off. Either the couple will continue to find new things to enjoy about one another, or they will separate. However, if the separation is forced, as it was here, it is easy to forget that feeling of familiarity and to be excited again when reunited. The weather symbolizes the two stages most literally. Hot for the passion, cold for the lack of continuing interest beyond the excitement and lust.