The phrase "clouding up" typically refers to the sky becoming overcast with clouds, indicating possible rain or inclement weather. Antonyms for "clouding up" would include phrases like "clearing up," "brightening up," or "clear skies." These antonyms suggest a positive change in the weather, with a return to sunny or pleasant conditions. Other antonyms might include phrases like "drying out," "warming up," or "calming down," which suggest a return to dry, warm, or tranquil conditions. Whether the weather is cooperating or not, having a rich vocabulary to describe it can help us better appreciate the natural world around us.