| Canyon phenomenon |
| Coastal phenomenon |
| Pre-migraine headache phenomenon |
| Agricultural phenomenon sometimes linked to UFOs |
| Autumn lunar phenomenon |
| Phenomenon observed in receding galaxies ... and in the answers to this puzzle's asterisked clues? |
| Alpine phenomenon |
| Day-care workers headaches |
| Pop culture phenomenon |
| Stock market phenomenon |
| First light ... or a phenomenon suggested by this puzzle's seven sets of circled letters? |
| Headache cause |
| Eerie phenomenon |
| Coaches' headaches |
| Depression phenomenon |
| Travelers' headaches |
| Acoustic phenomenon |
| Eclipse phenomenon. |
| Polar region phenomenon |
| Final sign of a highway headache |
| Actor's headache, frequently |
| Phenomenon of the Colorado River. |
| Headaches |
| Excavator overlooked secondary weather phenomenon |
| Unexplained phenomenon |
| Analgesic for a post-snorkeling headache? |
| Gardener's headache? |
| Orbiting phenomenon |
| Flavor enhancer that can cause headaches: Abbr. |
| Plant used as an herbal remedy for headaches |