| Abbreviation | Definition |
|---|---|
| GWC3 | Geophysical Weather phenomena, unusual Clouds: Polar Bands |
| GWC4 | Unusual Clouds: Miniature Thunderclouds |
| GWC5 | Unusual Clouds: Noisy Clouds |
| GWC6 | Unusual Clouds: Noctilucent Clouds |
| GWC7 | Unusual Clouds: Ring Clouds |
| GWC8 | Unusual Clouds: Thunderclouds Affecting the Ionosphere |
| GWC9 | Geophysical Weather phenomena, unusual Clouds: Circular Holes in Cloud Decks |
| GWDS | Graphics Weather Displays Systems |
| GWIM | Global Warming Impact Model |
| GWP | Groundwater Management |
| H | High |
| HAEV | High Air Entry Value |
| HAL | Hot Air Leveling |
| HAL | Hot Air Levelling |
| HAM | Heat, Air, and Moisture |
| HAP | Hazardous Air Pollutant |
| HAZ | Heat Affected Zone |
| HCDT | Historical Climate Data Temperature |
| HCDTS | Historical Climate Data Temperature Summary |
| HDD | Heat Degree Days |