| pr_wthr_code | # ambrose records | description |
| NULL | 249 | not assigned |
| 0 | 3,402 | Cloud development not observed |
| 1 | 2,865 | Clouds generally dissolving or becoming less developed |
| 2 | 6,524 | State of the sky unchanged |
| 3 | 3,176 | Clouds generally forming or developing |
| 4 | 27 | Visibility reduced by smoke |
| 5 | 2,110 | Haze |
| 6 | 9 | Widespread dust in suspension in the air, not raised by wind |
| 7 | 3 | Dust or sand raised by wind at or near station at time of observation, but no well developed dust or sand whirls or storms |
| 8 | 3 | Well-developed dust or sand whirls seen at or near station during preceding hour or time of observation but no dust or sand storm |
| 9 | 0 | Dust storm or sand storm within sight duringobservation or during preceding hour |
| 10 | 904 | Light fog (visibility 1,100 yards or more) |
| 11 | 3 | Patches of shallow fog or ice fog at the station, not deeper than about 10 meters |
| 12 | 7 | More or less continuous shallow fog or ice fog, not deeper than about 10 meters |
| 13 | 11 | Lightning visible, no thunder heard |
| 14 | 2 | Precipitation within sight, not reaching the surface of the sea |
| 15 | 5 | Precipitation within sight, not reaching the surface of the sea, but more than 5 km. from the ship |
| 16 | 4 | Precipitation within sight, reaching the surface of the sea, near to, but not at the ship |
| 17 | 0 | Thunderstorm, but no precipitation at time of observation |
| 18 | 3 | Squalls at or within sight of the ship during the preceding hour or at the time of observation |
| 19 | 0 | Funnel cloud or water spout at or within sight of the ship during the preceding hour or at time of observation |
| 20 | 153 | Drizzle (not freezing) or snow grains |
| 21 | 194 | Rain (not freezing) |
| 22 | 34 | Snow |
| 23 | 7 | Rain and snow or ice pellets, type(a) |
| 24 | 2 | Freezing drizzle or freezing rain |
| 25 | 37 | Shower(s) of rain |
| 26 | 5 | Shower(s) of snow or of rain and snow |
| 27 | 3 | Shower(s) of hail (ice pellets, type(b), snow pellets), or of rain and hail (ice pellets, type(b), snow pellets) |
| 28 | 36 | Fog or ice fog |
| 29 | 12 | Thunderstorm, with or without precipitation |
| 30 | 1 | Slight or moderate duststorm or sandstaorm has decreased during the preceding hour |
| 40 | 39 | Fog or ice fog at a distance at the time of observation, but not at the ship during the preceding hour, the fog or ice extending to a level above that of the observer |
| 41 | 29 | Fog or ice fog in patches |
| 42 | 56 | Fog or ice fog, sky visible has become thinner during the preceding hour |
| 43 | 71 | Fog or ice fog, sky invisible has become thinner during the preceding hour |
| 44 | 130 | Fog or ice fog, sky visible no appreciable change during the preceding hour |
| 45 | 333 | Fog or ice fog, sky invisible no appreciable change during the preceding hour |
| 46 | 119 | Fog or ice fog, sky visible has begun or has become thicker during the preceding hour |
| 47 | 203 | Fog or ice fog, sky invisible has begun or has become thicker during the preceding hour |
| 50 | 173 | Drizzle, not freezing, intermittent slight at time of observation |
| 51 | 217 | Drizzle, not freezing, continuous slight at time of observation |
| 52 | 5 | Drizzle, not freezing, intermittent moderate at time of observation |
| 53 | 28 | Drizzle, not freezing, continuous moderate at time of observation |
| 54 | 1 | Drizzle, not freezing, intermittent heavy (dense) at time of observation |
| 55 | 7 | Drizzle, not freezing, continuous heavy (dense) at time of observation |
| 56 | 3 | Drizzle, freezing, slight |
| 57 | 1 | Drizzle, freezing, moderate or heavy (dense) |
| 58 | 15 | Drizzle and rain, slight |
| 59 | 2 | Drizzle and rain, moderate or heavy |
| 60 | 132 | Rain, not freezing, intermittent, slight at time of observation |
| 61 | 261 | Rain, not freezing, continuous, slight at time of observation |
| 62 | 16 | Rain, not freezing, intermittent, moderate at time of observation |
| 63 | 92 | Rain, not freezing, continuous, moderate at time of observation |
| 64 | 10 | Rain, not freezing, intermittent, heavy at time of observation |
| 65 | 32 | Rain, not freezing, continuous, heavy at time of observation |
| 66 | 1 | Rain, freezing, slight |
| 67 | 6 | Rain, freezing, moderate or heavy |
| 68 | 14 | Rain or drizzle and snow, slight |
| 69 | 4 | Rain or drizzle and snow, moderate or heavy |
| 70 | 48 | Intermittent fall of snowflakes, slight at time of observation |
| 71 | 87 | Continuous fall of snowflakes, slight at time of observation |
| 72 | 7 | Intermittent fall of snowflakes, moderate at time of observation |
| 73 | 45 | Continuous fall of snowflakes, moderate at time of observation |
| 74 | 0 | Intermittent fall of snowflakes, heavy at time of observation |
| 75 | 51 | Continuous fall of snowflakes, heavy at time of observation |
| 76 | 0 | Ice prisms (with or without fog) |
| 77 | 9 | Snow grains, with or without fog |
| 79 | 6 | Ice pellets, type (a) (sleet US definition) |
| 80 | 15 | Rain shower(s), slight |
| 81 | 7 | Rain shower(s), moderate or heavy |
| 82 | 1 | Rain shower(s), violent |
| 83 | 3 | Shower of rain and snow mixed, slight |
| 84 | 2 | Shower of rain and snow mixed, moderate or heavy |
| 85 | 12 | Snow shower(s), slight |
| 86 | 2 | Snow shower(s), moderate or heavy |
| 87 | 2 | Slight showers of snow or ice pellets, type (b), with or without rain and/or snow mixed |
| 88 | 2 | Moderate or heavy showers of snow or ice pellets, type (b), with or without rain and/or snow mixed |
| 90 | 1 | Moderate or heavy showers of hail, with or without rain or rain and snow, slight mixed, not associated with thunder |
| 91 | 1 | Slight rain at time of observation, thunderstorm during preceding hour but not at time of observation |
| 92 | 2 | Moderate or heavy rain at time of observation, thunderstorm during preceding hour but not at time of observation |
| 93 | 3 | Moderate or heavy snow or rain and snow mixed or hail, at time of observation, thunderstorm during preceding hour but not at time of observation |
| 94 | 2 | Slight snow or rain and snow mixed or hail, at time of observation, thunderstorm during preceding hour but not at time of observation |
| 95 | 4 | Thunderstorm, slight or moderate, without hail, but with rain and/or snow at time of observation |
| 97 | 3 | Thunderstorm, heavy, without hail, but with rain and/or snow at time of observation |
| 99 | 2 | Thunderstorm, heavy, with hail at time of observation |