Degree days: technical details
The base temperature used to calculate degree days in the UK is 15.5ºC, because at this temperature most UK buildings do not need supplementary heating.
Degree days is a measure of the difference between the baseline and the actual outdoor temperature multiplied by the number of days. For example - the temperature measured hourly records a temperature of:
7.5ºC for 48 hours the degree days total would be: (15.5 - 7.5) x 2 = 16
Note - it is not possible to have a negative degree day value as when the outdoor temperature exceeds 15.5ºC no heating is needed. When the outdoor temperature does exceed the 15. 5ºC baseline, then the degree days are set to zero.
August 2010 degree day data
Degree days are measured in 18 locations across the country, here is the data for August 2010:
|
|
|
Region
|
August
2010
|
August
2009
|
August 20 year average
|
|
1
|
Thames Valley
|
34
|
13
|
17
|
|
2
|
South Eastern
|
46
|
20
|
27
|
|
3
|
Southern
|
9
|
6
|
30
|
|
4
|
South Western
|
30
|
18
|
21
|
|
5
|
Severn Valley
|
30
|
16
|
17
|
|
6
|
Midland
|
48
|
30
|
32
|
|
7
|
West Pennines
|
63
|
33
|
35
|
|
8
|
North Western
|
91
|
43
|
48
|
|
9
|
Borders
|
67
|
35
|
50
|
|
10
|
North Eastern
|
64
|
32
|
44
|
|
11
|
East Pennines
|
40
|
24
|
31
|
|
12
|
East Anglia
|
38
|
24
|
31
|
|
13
|
West Scotland
|
62
|
40
|
52
|
|
14
|
East Scotland
|
72
|
47
|
56
|
|
15
|
NE Scotland
|
134
|
42
|
63
|
|
16
|
Wales
|
42
|
35
|
35
|
|
17
|
Northern Ireland
|
66
|
37
|
46
|
|
18
|
NW Scotland
|
82
|
58
|
69
|
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