0 0 CLOUD COVERING 1/2 OR LESS OF THE SKY THROUGHOUT THE APPROPRIATE PERIOD
1 1 CLOUD COVERING MORE THAN 1/2 OF THE SKY DURING PART OF THE APPROPRIATE PERIOD AND COVERING 1/2 OR LESS DURING PART OF THE PERIOD
2 2 CLOUD COVERING MORE THAN 1/2 OF THE SKY THROUGHOUT THE APPROPRIATE PERIOD
3 3 SANDSTORM, DUSTSTORM OR BLOWING SNOW
4 4 FOG OR ICE FOG OR THICK HAZE
5 5 DRIZZLE
6 6 RAIN
7 7 SNOW, OR RAIN AND SNOW MIXED
8 8 SHOWER(S)
9 9 THUNDERSTORM(S) WITH OR WITHOUT PRECIPITATION
10 10 NO SIGNIFICANT WEATHER OBSERVED
11 11 VISIBILITY REDUCED
12 12 BLOWING PHENOMENA, VISIBILITY REDUCED
13 13 FOG
14 14 PRECIPITATION
15 15 DRIZZLE
16 16 RAIN
17 17 SNOW OR ICE PELLETS
18 18 SHOWERS OR INTERMITTENT PRECIPITATION
19 19 THUNDERSTORM
31 31 MISSING VALUE
