| Code figure | ||
|---|---|---|
| 0 | Increasing, then decreasing; atmospheric pressure the same or higher than three hours ago | |
| 1 | Increasing, then steady; or increasing, then increasing more slowly | Atmospheric pressure now higher than three hours ago |
| 2 | Increasing (steadily or unsteadily)* | |
| 3 | Decreasing or steady, then increasing; or increasing, then increasing more rapidly | |
| 4 | Steady; atmospheric pressure the same as three hours ago* | |
| 5 | Decreasing, then increasing; atmospheric pressure the same or lower than three hours ago | Atmospheric pressure now lower than three hours ago |
| 6 | Decreasing, then steady; or decreasing, then decreasing more slowly | |
| 7 | Decreasing (steadily or unsteadily)* | |
| 8 | Steady or increasing, then decreasing; or decreasing, then decreasing more rapidly | |