Temperature related variables

Length of the growing season

 
 

Figure 14 - Length of the growing season (in days) each year for Scottish regions, from 1961 to 2004, with smoothed curves showing a running average.

Table 8 - Changes in growing season length (in days) from 1961 to 2004. Values in bold show that we are 95% confident (statistically) that the change is part of a measurable trend.

 

North Scotland East Scotland West Scotland Scotland
Growing season length (days) 31.1% 32.5% 36.7% 33.2%

 

Regional trends

 

  • In the early 1960s, typical values were a growing season of about 213 days in East Scotland, 217 days in North Scotland and 237 days in the West.
  • All regions have seen an increase of more than four weeks in the length of the growing season since 1961.
  • The increase in the length of the growing season is part of a clear trend in all regions.
  • The West has shown the greatest increase and the North the least.

Spatial trends

 

  • The greatest increases in the length of the growing season are in coastal areas and the Shetland Islands where the season has extended by two months, or more.
  • The length of the growing season has changed very little since 1961 in some of the more mountainous areas.
  • A few upland areas show a reduction in the length of the growing season of up to eight days.

Future trends

 

  • The UKCIP02 scenarios show an increase in the length of the growing season of between 20 and 60 days by the 2080s.
  • This is similar to the level of change (33 days for Scotland as a whole) that we have already seen since 1961.
  • The UKCIP02 scenarios suggest the increase will be greater in the east than in the west, but the information from observations shows the opposite pattern.

 

Figure 15 - Pattern of change in the length of the growing season (in days) from 1961 to 2004 calculated from the extended UKCIP02 dataset.