Isopleths of monthly mean temperature (1902-1954) at 5 positions 2° 0° 2° 4° Longitude [°W/°E] Month 1 23456789 10 11 Month 1 2 3 4 5 6 7 8 9 10 11 12 Month 1 2 3 4 5 6 7 8 9 10 11 12 Month i—i—r 7 8 9 10 11 12 -10 10- -20 20- 30 30 -40 — 40 - E. 50 £ 50 - 0 J 60 ° 60 -70 70- -80 80- -90 90- MOO 100- 1 2 3 4 5 6 7 ~i i r~ 8 9 10 ~ r 11 12 0 10 20 -30 -40 50 60 70 80 90 100