Can the whisper of a Message spell be heard over loud ambient noise?

I want to use the Message cantrip to coordinate with an ally in secret. However, I want to do this during a loud battle (powerful spells being flung back and forth in a highly destructible environment). The text of the spell says:

You … whisper a message. The target … hears the message and can reply in a whisper that only you can hear.

Since the message is whispered, does that mean the target may not be able to make out what I’m saying over the din of battle? Or does “the target hears the message” imply that the spell’s magic ensures that the message is audible?