I6 - Station id
I2 - Unknown
I4 - Data year
A4 - Data type (For precip: 366 F4.2 For temperature: 366 I4)
PRCP - precipitation daily accumulation (hundredths of inches)
TMAX - maximum daily air temperature (F)
TMIN - minimum daily air temperature (F)
Missing values are denoted as 9999.
Day 366 of non-leap years is denoted as 9999.