import xarray as xr
url = 'http://www.ncei.noaa.gov/thredds/dodsC/avhrr-patmos-x-cloudprops-noaa-asc-fc/files/2003/patmosx_v05r03_NOAA-17_asc_d20030101_c20140314.nc'
# Decoding using decode_cf
ds=xr.open_dataset(url, decode_cf=True)
ds.cloud_fraction
<xarray.DataArray 'cloud_fraction' (time: 1, latitude: 1800, longitude: 3600)>
[6480000 values with dtype=float32]
Coordinates:
  * latitude   (latitude) float32 -89.947815 -89.84893 -89.74731 -89.64843 ...
  * longitude  (longitude) float32 -179.94507 -179.84619 -179.7473 ...
  * time       (time) datetime64[ns] 2003-01-01
Attributes:
    standard_name:  cloud_area_fraction
    long_name:      cloud fraction computed over a 3x3 pixel array at the nat...
    actual_range:   [0. 1.]
    valid_range:    [-127  127]
    scaled:         1
    _ChunkSizes:    [  1 361 361]

ds.cloud_fraction.plot()
#The cloud fraction data should be scaled to be a percentage between 0 and 1, but it is not. 

#Manually decoding cloud_fraction
ds=xr.open_dataset(url, decode_cf=False)

ds.cloud_fraction
<xarray.DataArray 'cloud_fraction' (time: 1, latitude: 1800, longitude: 3600)>
[6480000 values with dtype=int8]
Coordinates:
  * latitude   (latitude) int16 -32748 -32712 -32675 -32639 -32603 -32566 ...
  * longitude  (longitude) int16 -32757 -32739 -32721 -32703 -32685 -32666 ...
  * time       (time) float32 1041379200.0
Attributes:
    _Unsigned:      false
    standard_name:  cloud_area_fraction
    long_name:      cloud fraction computed over a 3x3 pixel array at the nat...
    coordinates:    latitude longitude
    actual_range:   [0. 1.]
    valid_range:    [-127  127]
    scale_factor:   0.003937008
    add_offset:     0.5
    _FillValue:     -128
    scaled:         1
    _ChunkSizes:    [  1 361 361]

cloud_fract_manual = ds.cloud_fraction * ds.cloud_fraction.scale_factor + ds.cloud_fraction.add_offset
cloud_fract_manual.plot()