# Obstructions to visibility

Obstructions to visibility are returned as a code. See the table below for all possible code values and their meaning.

:::note{title="Light, moderate, or heavy?"}

A code may end with `-` for light intensity or `+` for heavy intensity. A code with no symbol means moderate intensity.

**Examples:**

- `S-` = light snow.
- `S` = moderate snow.
- `S+` = heavy snow.

:::

| Code | Obstruction             |
| ---- | ----------------------- |
| L    | Drizzle                 |
| R    | Rain                    |
| S    | Snow                    |
| T    | Thunderstorm            |
| UP   | Undefined precipitation |
| IP   | Ice pellets             |
| A    | Heavy thunderstorm/hail |
| F    | Fog                     |
| HZ   | Haze                    |
| D    | Dust                    |
| I    | Ice                     |
| IC   | Ice crystals            |
| IF   | Ice fog                 |
| IPW  | Ice pellets shower      |
| BD   | Blowing dust            |
| BN   | Blowing sand            |
| BS   | Blowing snow            |
| GF   | Ground fog              |
| SG   | Snow granules           |
| ZR   | Freezing rain           |
| ZL   | Freezing drizzle        |
| K    | Smoke                   |
| SP   | Snow pellets            |
| RW   | Rain shower             |
| SW   | Snow shower             |
| RS   | Rain/snow               |