| Abbreviation | Definition |
|---|---|
| C | Calm (no wind) |
| C | Centigrade |
| C | Cloud |
| C | Conditions |
| C | Cool |
| C4I | Command, Control, Communications, Computers, and Information |
| CAC | Canadian Avalanche Centre |
| CAI | Cold Air Induction |
| CAIT | Climate Analysis Indicators Tool |
| CAO | Cold Air Outbreak |
| CAR | Cloud Absorption Radiometer |
| CARDS | Comprehensive Aerological Reference Data Set |
| CART | Computer Assisted Radar Tomography |
| CASA | Carnegie-Ames-Stanford Approach |
| CAT | Cumulative Average Temperature |
| CATS | Calm After The Storm |
| CAV | Constant Angular Velocity |
| CAVOK | Clouds And Visibility OK |
| CAWIS | Committee for Automated Weather Information Systems |
| CB | Corona Borealis |