Final answer:
The sky in this context is described as having dark, ominous clouds, suggesting a stormy weather.
Step-by-step explanation:
The sky in this context is described as having dark, ominous clouds. In the passage, it mentions a cloud-bank that darkened the lower edge of the setting sun and eventually obscured its fiery red heart. Additionally, there is mention of thunder and the approaching storm. These details suggest that the sky is stormy and filled with dark, ominous clouds.