Introduction The ISD-Lite data contain a fixed-width formatted subset of the complete Integrated Surface Data (ISD) for a select number of observational elements. The data are typically stored in a single file corresponding to the ISD data, i.e. one file per station per year. For more information on the ISD-Lite format, consult the ISD-Lite technical document. Data Format Field 1: Pos 1-4, Length 4: Observation Year Year of observation, rounded to nearest whole hour Field 2: Pos 6-7, Length 2: Observation Month Month of observation, rounded to nearest whole hour Field 3: Pos 9-11, Length 2: Observation Day Day of observation, rounded to nearest whole hour Field 4: Pos 12-13, Length 2: Observation Hour Hour of observation, rounded to nearest whole hour Field 5: Pos 14-19, Length 6: Air Temperature The temperature of the air UNITS: Degrees Celsius SCALING FACTOR: 10 MISSING VALUE: -9999 Field 6: Pos 20-24, Length 6: Dew Point Temperature The temperature to which a given parcel of air must be cooled at constant pressure and water vapor content in order for saturation to occur. UNITS: Degrees Celsius SCALING FACTOR: 10 MISSING VALUE: -9999 Field 7: Pos 26-31, Length 6: Sea Level Pressure The air pressure relative to Mean Sea Level (MSL). UNITS: Hectopascals SCALING FACTOR: 10 MISSING VALUE: -9999 Field 8: Pos 32-37, Length 6: Wind Direction The angle, measured in a clockwise direction, between true north and the direction from which the wind is blowing. UNITS: Angular Degrees SCALING FACTOR: 1 MISSING VALUE: -9999 *NOTE: Wind direction for calm winds is coded as 0.

Field 9: Pos 38-43, Length 6: Wind Speed Rate The rate of horizontal travel of air past a fixed point. UNITS: meters per second SCALING FACTOR: 10 MISSING VALUE: -9999 Field 10: Pos 44-49, Length 6: Sky Condition Total Coverage Code The code that denotes the fraction of the total celestial dome covered by clouds or other obscuring phenomena. MISSING VALUE: -9999 DOMAIN: 0: None, SKC or CLR 1: One okta - 1/10 or less but not zero 2: Two oktas - 2/10 - 3/10, or FEW 3: Three oktas - 4/10 4: Four oktas - 5/10, or SCT 5: Five oktas - 6/10 6: Six oktas - 7/10 - 8/10 7: Seven oktas - 9/10 or more but not 10/10, or BKN 8: Eight oktas - 10/10, or OVC 9: Sky obscured, or cloud amount cannot be estimated 10: Partial obscuration 11: Thin scattered 12: Scattered 13: Dark scattered 14: Thin broken 15: Broken 16: Dark broken 17: Thin overcast 18: Overcast 19: Dark overcast Field 11: Pos 50-55, Length 6: Liquid Precipitation Depth Dimension - One Hour Duration The depth of liquid precipitation that is measured over a one hour accumulation period. UNITS: millimeters SCALING FACTOR: 10 MISSING VALUE: -9999 *NOTE: Trace precipitation is coded as -1 Field 12: Pos 56-61, Length 6: Liquid Precipitation Depth Dimension - Six Hour Duration The depth of liquid precipitation that is measured over a six hour accumulation period. UNITS: millimeters SCALING FACTOR: 10 MISSING VALUE: -9999 *NOTE: Trace precipitation is coded as -1