Introduction

 
 

Table 1 - Summary of the main findings by variable, region and season and a comparison of the trend for 1961 to 2004 with expectations for the climate in the future as presented by the UKCIP02 scenarios (Hulme et al., 2002).

 

Red Arrow = Upward Trend Blue Arrow = Downward Trend, blank means no trend detectable

 

Table 1
Variable Change by season Region Expected future trend
(from UKCIP02 scenarios)
North East West
Annual Average
Temperature
Spring Upward Trend Upward Trend Upward Trend Possible increase in all seasons, greater in south than north. This matches the trends already seen.
Summer Upward Trend Upward Trend Upward Trend
Autumn Upward Trend Upward Trend Upward Trend
Winter   Upward Trend Upward Trend
Annual Upward Trend Upward Trend Upward Trend
24-hour maximum
temperature
Spring Upward Trend Upward Trend Upward Trend Maximum temperatures may increase in all seasons. The range of possible increases is
smallest in winter and greatest in autumn. This matches trends we have already seen.
Summer Upward Trend Upward Trend Upward Trend
Autumn Upward Trend Upward Trend Upward Trend
Winter Upward Trend Upward Trend Upward Trend
Annual Upward Trend Upward Trend Upward Trend
24-hour minimum
temperature
Spring Upward Trend Upward Trend Upward Trend The minimum temperatures may increase more in winter than summer. This generally
matches the trends already seen.
Summer Upward Trend Upward Trend Upward Trend
Autumn   Upward Trend  
Winter   Upward Trend  
Annual Upward Trend Upward Trend Upward Trend
Daily
temperature
range
Spring       This range may increase most in summer. We cannot find a trend in the information we have for summer, but some regions
are showing an increasing trend in other seasons.
Summer      
Autumn Upward Trend    
Winter Upward Trend   Upward Trend
Annual Upward Trend    
Heating degree days Annual Downward Trend Downward Trend Downward Trend This may reduce in the future, which is in line with the trend already seen, but the possible reduction by the 2080s is 50% to 300% greater than that experienced so far.
Growing
degree days
Annual       No estimates have been made in the UKCIP02 scenarios for this measure.
Length of the
growing season
Annual Upward Trend Upward Trend Upward Trend A possible increase in the length of the growing season of 20 to 60 days by the 2080s. We have seen a similar trend but the spatial pattern is different.
Growing season start and end dates Start Downward Trend Downward Trend Downward Trend Estimates for the start of the growing season are similar to those we have already seen, but suggest a later end to the growing
season than has been seen already.
End Upward Trend Upward Trend Upward Trend
Extreme
temperature
range
Annual       No estimates have been made in the UKCIP02 scenarios for this measure.
Length of
summer heat
waves and winter cold spells
Summer       No estimates have been made in the UKCIP02 scenarios for this measure.
Winter   Downward Trend Downward Trend