Is the climate changing?
The way you present the data affects your judgment
Chris Goodall
At Magdalen College School, Oxford
March 2010
Oxford 1971–2000 averages
Oxford (63 m AMSL)
Max Temp Min TempDays of Air Frost
Sunshine RainfallDays ofRainfall≥ 1mm
Wind at 10 m
Month [°C] [°C] [days] [hours] [mm] [days] [knots]
Jan 7.2 1.9 8.8 58.0 57.5 11.5 N/A
Feb 7.6 1.7 8.5 72.0 42.6 9.2 N/A
Mar 10.3 3.4 4.0 107.9 50.0 10.5 N/A
Apr 12.8 4.7 2.1 150.0 46.2 8.7 N/A
May 16.5 7.5 0.2 191.9 53.9 9.1 N/A
Jun 19.5 10.5 0.0 187.8 54.5 8.7 N/A
Jul 22.3 12.8 0.0 205.5 38.2 6.7 N/A
Aug 21.9 12.6 0.0 193.8 54.4 7.8 N/A
Sep 18.6 10.5 0.0 138.6 58.9 9.1 N/A
Oct 14.4 7.4 0.7 108.2 61.8 10.6 N/A
Nov 10.1 4.3 4.5 72.0 59.4 10.1 N/A
Dec 8.0 2.8 7.3 51.8 64.7 10.9 N/A
Year 14.1 6.7 36.1 1537.4 642.0 112.9 N/A
Source: Met Office
Average
OxfordLocation: 4509E 2072N, 63 metres amslEstimated data is marked with a * after the value.Missing data (more than 2 days missing in month) is marked by --
Sunshine data taken from an automatic Kipp & Zonen sensor markedwith a #, otherwise sunshine data taken from a Campbell Stokesrecorder.yyyy mm tmax tmin af rain sun
degC degC day mm hours
1853 1 8.4 2.7 4 62.8 ---1853 2 3.2 -1.8 19 29.3 ---1853 3 7.7 -0.6 20 25.9 ---1853 4 12.6 4.5 0 60.1 ---1853 5 16.8 6.1 0 59.5 ---1853 6 20.1 10.7 0 82.0 ---1853 7 21.2 12.2 0 86.2 ---1853 8 20.2 10.8 0 72.3 ---1853 9 17.3 8.4 0 51.3 ---1853 10 13.9 7.4 0 102.3 ---1853 11 8.7 2.3 10 49.6 ---1853 12 3.7 -1.3 19 10.7 ---1854 1 6.7 1.5 11 54.5 ---1854 2 8.0 0.6 12 22.6 ---1854 3 11.2 2.2 8 10.6 ---1854 4 15.0 3.5 2 19.9 ---
Source: Met Office
Source data available online
0
5
10
15
20
25
1961-1991
1971-2000
2009
Oxford average daily maximum temperatures for three periods
Source: Met Office
0
2
4
6
8
10
12
14
1961-1991
1971-2000
2009
Oxford average daily minimum temperatures for three periods
Source: Met Office
1961-1990 1971-2000 2009
Average daily maximum(degrees Celsius)
Average daily minimum(degrees Celsius)
13.8 14.1 15.2
6.4 6.7 7.0
Summary Oxford data
Source: Met Office
0
1
2
3
4
5
6
7
Number of months in year with over 100mm rainfall
Source: Met Office
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1860 1910 1960 2010
Ten year moving average
Number of months in year with over 100mm rainfall
Source: Met Office
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1860 1910 1960 2010
Ten year moving average
Number of months in year with over 100mm rainfall
Source: Met Office
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1860 1910 1960 2010
Thirty year moving average
Number of months in year with over 100mm rainfall
Source: Met Office
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1860 1910 1960 2010
Thirty year moving average
Number of months in year with over 100mm rainfall
Source: Met Office
0
10
20
30
40
50
60
70
1850 1870 1890 1910 1930 1950 1970 1990 2010
Ten year moving average
Number of airfrost days per year
Source: Met Office
0
10
20
30
40
50
60
1860 1880 1900 1920 1940 1960 1980 2000 2020
Thirty year moving average
Number of airfrost days per year
Source: Met Office
Thirty year moving average
April airfrost days
0
0.5
11.5
2
2.5
33.5
4
4.5
1870 1890 1910 1930 1950 1970 1990 2010
Thirty year moving average
Source: Met Office
2020.5
2121.5
2222.5
2323.5
1850 1870 1890 1910 1930 1950 1970 1990 2010
Ten year moving average
Average daily July maximum temperatures
Source: Met Office
2020.5
2121.5
2222.5
2323.5
1850 1870 1890 1910 1930 1950 1970 1990 2010
Ten year moving average
Average daily July maximum temperatures
Source: Met Office
20.5
21
21.5
22
22.5
23
1860 1880 1900 1920 1940 1960 1980 2000 2020
Twenty year moving average
Average daily July maximum temperatures
Source: Met Office
21
21.5
22
22.5
23
1860 1880 1900 1920 1940 1960 1980 2000 2020
Thirty year moving average
Average daily July maximum temperatures
Source: Met Office
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
1860 1910 1960 2010
Ten year moving average
Average daily January minimum temperature
Source: Met Office
0
0.5
1
1.5
2
2.5
3
1860 1910 1960 2010
Twenty year moving average
Average daily January minimum temperature
Source: Met Office
0
0.5
1
1.5
2
2.5
1870 1890 1910 1930 1950 1970 1990 2010
Thirty year moving average
Average daily January minimum temperature
Source: Met Office
0
0.5
1
1.5
2
2.5
1870 1890 1910 1930 1950 1970 1990 2010
Thirty year moving average
Average daily January minimum temperature
What did this chart look like five years ago?
Source: Met Office
0
0.5
1
1.5
2
2.5
1870 1890 1910 1930 1950 1970 1990 2010
Thirty year moving average
2010
*
Average daily January minimum temperature
And what about this year?
Source: Met Office
1961-1990 1971-2000 2009
Average daily maximum(degrees Celsius)
Average daily minimum(degrees Celsius)
13.8 14.1 15.2
6.4 6.7 7.0
Summary Oxford data
Source: Met Office