Here are some possible English translations that capture the nuance of the phrase:
* It's raining again. (This emphasizes the repetition of the rain.)
* It just keeps raining. (This conveys a sense of frustration or weariness.)
* The rain never seems to stop. (This highlights the ongoing nature of the rain.)
* It's always raining. (This is a more literal translation.)
The best translation will depend on the context of the conversation.