The daily and monthly cloud data file format is a comma-delimited text file.
The data was derived from the average hourly cloud cover from sunrise to sunset, in oktas.

Clear denotes an average sky cover of 0-2 oktas.
Partly cloudy denotes an average sky cover of 3-5 oktas.
Cloudy denotes an average sky cover of 6-8 oktas.

NaN = not a number (missing data) defined as...
Daily Data: If more than 2 hours of observations are missing, the day is marked as NaN.
Monthly Data: If more than 5 days of observations are missing, the month is marked as NaN.


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Header for each data type
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Daily Data:
year, month, day, avg cloud cover (in oktas)


Monthly Data:
year, month, avg cloud cover (in oktas), # days clear, # days partly cloudy, # days cloudy









For additional information, visit http://www.climate.washington.edu/cloudcover