2 and 3 indicate a manned station, while codes 4 to 7 indicate an automatic station. h indicates the height above the surface for the base of the lowest cloud seen: 0 means from 0 to 100 feet or 0 to 50 meters, 9 means the base of clouds is 2500 meters or higher or that there are no clouds. VV indicates horizontal surface visibility: For codes 00 to 50, this indicates visibility in tenths of a kilometer (hectometers), for example "15" means 1.5 km. For codes 56 to 80, 50 is subtracted, and the resulting number indicates visibility in kilometers, for example "66" means 16 km. Codes 81 to 88 indicate visibility in a multiple of 5 km; "81" for 35 km, "88" for 70 km. Code 89 indicates visibility greater than 70 km; Codes 90 to 99 are used for shipboard observations, from "90" for less than mile visibility, "95" for 1 mile, "99" for greater than 30 miles. Nddff and 00fff: N: total cloud cover in eighths of the sky (oktas); "0" for no clouds, "4" for half () of the sky obscured, "8" for total cloud cover, "9" for an obscured sky or a situation where cloud cover can't be estimated, "/" for no measurement in the case of automatic stations. dd for true wind direction in tens of degrees, with "00" meaning "no wind", "18" for wind from the south (175° to 184°), "36" for wind from the north (355° to 004°). ff for wind speed, in the units specified in the YYGGiw group. If wind speed is 99 units or more, this group will have the code "99" and will immediately be followed by the group 00fff, with the wind speed indicated there instead. 1snTTT: air temperature. Code sn indicates the sign, 0 for positive, 1 for negative degrees; TTT has the temperature in tenths of a degree Celsius. 2snTdTdTd: dew point temperature. Like the preceding 1snTTT group, sn stands for the sign, and TdTdTd has the temperature in tenths of a degree Celsius. If sn is 9, the last three digits are instead relative humidity in percent, from "000" to "100". 3PoPoPoPo: air pressure at station level, in tenths of a hectopascal. If the pressure is more than 999.9 hPa, the leading thousands digit is dropped; for example 30240 means a pressure of 1024.0 hPa. 4PPPP: air pressure at sea level, in tenths