Sunshine related variables

Cloud cover

 
 

Figure 47 - Percentage cloud cover each year for Scottish regions, from 1961 to 2004, with smoothed curves showing a running average.

Regional trends

 

  • None of the changes show an obvious trend in cloud cover.
  • The cloud cover changes do not appear to be linked to sunshine hours. It may be that natural variability is hiding any underlying trend but it is much more likely that the difficulties in comparing records based on different observing methods is the cause.
  • The large reduction in recent years is likely to be due to the change in observing methods.

Future trends

 

  • The UKCIP02 scenarios estimate cloud amounts may increase slightly in winter by the 2080s, particularly in the northern half of Scotland, and may reduce in all other seasons. The greatest changes may take place in summer in the southern and eastern areas.
  • The patterns of change we have already seen do not match these predictions.