The tweet's caption was a dialogue made-up by the park's staff that translated from Nagasaki dialect to English as:
"It's raining cats and dogs, ain't it?"
"And the wind's blowing cats and dogs too!"
"Reckon we ain't gonna get much done today."
The post has since been retweeted over 13,000 times and received more than 11,700 likes.
Many Japanese Twitter users have also sent their well wishes to the capybaras for them to take care and not catch a cold from the rain.