r TABLE 2.

6
Daily extraterrestrial radiation (Ra) for different latitudes for the 15th day of the month1
1t
\ Y'-'11'-'..,_~ U I IVIV 111 ua y ·I ~
Northern Hemisphere Lat. Southern Hemisphere I ~
Jan Feb Mar A pr May Jun July Aug Sep Oct Nov Dec deg. Jan Feb Mar Apr May Jun Julv Auq Sep Oct Nov Dec 1
0.0 2.6 10.4 23.0 35.2 42.5 39.4 28.0 14.9 4 .9 0.1 0.0 70 41 .4 28.6 15.8 4.9 0.2 0.0 0.0 2.2 10.7 23 .5 37.3 45.3
0.1 3.7 11 .7 23.9 35.3 42.0 38.9 28.6 16.1 6 .0 0.7 0.0 68 41 .0 29.3 16.9 6.0 0.8 0.0 0.0 3.2 11.9 24.4 37.4 44 .7
0.6 4.8 12.9 24.8 35.6 41.4 38.8 29.3 17.3 7.2 1.5 0.1 66 40.9 30.0 _ ..18.1 7.2 1.5 0.1 0.5 4.2 13.1 25.4 37.6 44.1
1.4 5.9 14.1 25.8 35.9 41.2 38.8 30.0 18.4 8.5 2.4 0.6 ·64 41 .0 30.8 Hp 8.4 2.4 0.6 1.2 5.3 14.4 26.3 38.0 43 .9
2 .3 7.1 15.4 26.6 36.3 41 .2 39.0 30.6 19.5 9.7 3.4 1.3 62 41 .2 31 .5 20.4 9.6 3.4 1.2 2.0 6.4 15.5 27.2 38.3 43 .9
3.3 8.3 16.6 27.5 36.6 41 .2 39.2 31 .3 20 .6 10.9 4.4 2.2 60 41 .5 32.3 21 .5 10.8 4.4 2.0 2.9 7.6 16.7 28.1 38.7 43 .9
4.3 9.6 17.7 28.4 37.0 41 .3 39.4 32.0 21 .7 12.1 5.5 3.1 .58 41.7 33.0 22 .6 12.0 5.5 2.9 3.9 8.7 17.9 28.9 39.1 44.0
5.4 10.8 18.9 29 .2 37.4 41 .4 39.6 32.6 22.7 13.3 6.7 4.2 56 42 .0 33.7 23.6 13.2 6.6 3.9 4 .9 9.9 19.0 29.8 39.5 44.1
6 .5 12.0 20.0 30.0 37.8 41 .5 39.8 33.2 23 .7 14.5 7.8 5.2 54 42.2 34.3 24.6 14.4 7.7 4.9 6.0 11.1 20.1 30.6 39.9 44.3
7 .7 13.2 21 .1 30.8 38.2 41 .6 40.1 33.8 24.7 15.7 9.0 6.4 52 42.5 35.0 25.6 15.6 8.8 6.0 7.1 12.2 21 .2 31.4 40.2 44.4
8.9 14.4 22 .2 31.5 38.5 41 .7 40 .2 34.4 25.7 16.9 10.2 7.5 50 42.7 35.6 26.6 16.7 10.0 7.1 8.2 13.4 22.2 32.1 40.6 44.5
10.1 15.7 23 .3 32.2 38.8 41 .8 40.4 34.9 26.6 18.1 11 .4 8.7 ' 48 42.9 36.2 27.5 17.9 11 .1 8.2 9.3 14.6 23.3 32.8 40.9 44.5
40 .6 35.4 27 .5 19.2 12.6 9.9 .. 46 . 43.0 36.7 28.4 19.0 12.3 9.3 10.4 15.7 24.3 33.5 41.1 44.6
11 .3 16.9 24.3 32.9 39.1 . 41 .9
18.0 25.3 33.5 39.3 41.9 40.7 35.9 28.4 20.3 13.9 11 .1 44 43.2 37.2 29.3 20.1 13.5 10.5 11 .6 16.8 25.2 34. 1 41.4 44.6
12.5
34 .1 39.5 41 .9 40.8 36.3 29.2 21.4 15.1 12.4 42 43.3 37.7 30.1 21 .2 14.6 11 .6 12.8 18.0 26.2 34.7 41.6 44.6
13.8 19.2 26 .3
39.7 41 .9 40.8 36.7 30.0 22.5 16.3 13.6 40 43.4 38.1 30.9 22.3 15.8 12-.8 13.9 19.1 27.1 35.3 41.8 44.6
15.0 20.4 27 .2 34.7
41 .8 40.8 37.0 30.7 23.6 17.5 14.8 38 43.4 38.5 31 .7 23.3 16.9 13.9 15.1 20.2 28.0 35.8 41.9 44.5
16.2 21.5 28.1 35.2 39.9
40.8 37.4 31 .5 24.6 18.7 16.1 36 43.4 38.9 32.4 24.3 18.1 15.1 16.2 21 .2 28.8 36. 3 42.0 44.4
17 .5 22 .6 29 .0 35.7 40 .0 41 .7
37.6 32.1 25 .6 19.9 17.3 34 43.4 39.2 33.0 25.3 19.2 16.2 17.4 22.3 29.6 36. 7 42.0 44.3
18 .7 23.7 29.9 36.1 40.0 41.6 40.8
32.8 26.6 21 .1 18.5 32 43.3 39.4 33.7 26.3 20.3 17.4 18.5 23.3 30.4 37.1 42.0 44.1
19.9 24 .8 30.7 36.5 40.0 41.4 40.7 37.9
33.4 27 .6 22.2 19.8 30 43.1 39.6 34.3 27.2 21 .4 18.5 19.6 24.3 31 .1 37. 5 42.0 43.9
21 .1 25.8 31.4 36.8 40 .0 41 .2 40.6 38.0
33.9 28.5 23.3 21 .0 28 43.0 39.8 34.8 28.1 22.5 19.7 20.7 25.3 31.8 37.8 41.9 43.6
22.3 26.8 32 .2 37.1 40.0 40.9 40.4 38.2
29.3 24.5 22.2 26 42.8 39.9 35.3 29.0 23.5 20.8 21 .8 26.3 32.5 38.0 41.8 43.3
27 .8 32.8 37.4 39.9 40.6 40.2 38.3 34.5
23.4 23.3 24 42.5 40.0 35.8 29.8 24.6 21.9 22.9 27.2 33.1 38.3 41.7 43.0
37.6 39.7 40.3 39.9 38.3 34.9 30.2 25.5
24 .6 28.8 33.5 40.1 36.2 30.6 25.6 23.0 24.0 28.1 33.7 38.4 41.4 42.6
40 .0 39.6 38.4 35.4 31 .0 26.6 24.5 22 42.2
25 .7 29.7 34.1 37.8 39.5 24.1 25.0 28.9 34.2 38.6 41 .2 42.1
39.3 38.3 35.8 31.8 27.7 25.6 20 41 .9 40.0 36.6 31 .3 26.6
26 .8 30.6 34.7 37.9 39.3 39.5 26.0 29.8 34. 7 38.7 40.9 41.7
38.2 36.1 32.5 28.7 26.8 18 41 .5 40.0 37.0 32.1 27.5 25.1
27.9 31 .5 35.2 38.0 39.0 39.1 38.9 30.6 35.2 38.7 40.6 41 .2
36.4 33.2 29.6 27.9 16 41.1 39.9 37.2 32.8 28.5 26.2 27.0
28.9 32.3 35.7 38.1 38.7 38.6 38.5 38.1 35.6 38.7 40.2 40.6
30.6 28.9 14 40.6 39.7 37.5 33.4 29.4 27.2 27.9 31.3
36.1 38.1 38 .4 38.1 38.1 38.0 36.7 33.9 39.8 40.0
29 .9 33.1 12 40.1 39.6 37.7 34.0 30.2 28.1 28.9 32.1 36.0 38.6
38.0 37.6 37.6 37.8 36.9 34.5 31 .5 30.0 39.4
30.9 33.8 36.5 38.0 39.3 37.8 34.6 31 .1 29.1 29.8 32.8. 36.3 38.5 39.3
37.1 37.5 37.1 35.1 32.4 31 .0 10 39.5
31 .9 34.5 36.9 37.9 37.6 37.0 35.1 31.9 30.0 30.7 33.4 36 .6 38.4 38.8 38 7
37.2 37.2 35.6 33.3 32.0 8 38.9 39.0 37.9
32.8 35.2 37.2 37.8 37.1 36.3 36.5 32.7 30.9 31.5 34.0 36 .8 38.2 38.2 38 0
37.3 36.1 34.1 32.9 6 38.3 38.7 38.0 35.6
33.7 35.8 37.4 37.6 36.6 35.7 35.9 36.9 32.3 34.6 37.0 38.0 37 6 37.2
36.6 34.9 33.9 4 37.6 38.3 38.0 36.0 33.4 31 .8
37.6 37.4 36.0 35.0 35.3 36.5 37.3 35.2 37 .1 37.7 37.0 36.4
34.6 36.4 34.8 2 36.9 37.9 38.0 36.4 34.1 32.6 33. 1
35.4 34.2 34.6 36.1 37.3 37.0 35.6 37.4 36.3 356
35.4 37.0 37.8 37.1 37.5 37.9 36.8 34.8 33.4 33.9 35.7 37.2 N
37.2 37.4 36.3 35.6 0 36.2 .....
36.2 37.5 37.9 36.8 34.8 33.4 33.9
-·
35.7
--' ..
_ ... _ 1 ..... .... ,..,. .. .,..,t 0/_ \ r.l C
-.l ~ ,,.,,,,,,,,,,,i m,~r ::,II ,fav~ within thP. month . Onlv for hiah latitudes c::ireater than 55° (N or S) (l)
I II IC I.., • .. uoY OT me monm p
\/_I_ __ .J: _ _ ,.... r:::.
A
a UI
- - .1. L.- ,4
during w inter months deviations may be more than 1%.
2 Values can be converted to equ ivalent values in mm/day by dividing by Lambda = 2.45.
 TABLE 2.7
Mean daylight hours (N) for different latitudes for the 15th of the month 1 ""C
24 (Eq . 34)
N = -ws
7t
Lat. Southern Hemisphere
Northern Hemisphere Jun July Aug Sep Oct Nov Dec
Nov Dec deg. Jan Feb Mar A pr May
Jan Feb Mar Apr May Jun July Au g Sep Oct 6.4 11 .2 15.7 21 .7 24 .0
70 24.0 17.4 13.0 8.4 2.7 0.0 0 .0
0.0 6.6 11.0 15.6 21.3 24.0 24.0 17.6 12.8 8.3 2.3 0.0 11 .3 15.3 19 .9 24 .0
16.7 12.9 8.7 4 .3 0.0 1.7 7 .0
11 .1 15.3 19.7 24.0 22.3 17.0 12.7 8.7 4.1 0.0 68 21 .9 18.8 22.1
2.1 7.3 9.1 5.3 2.0 3.7 7 .6 11 .3 15.0
20.3 16.4 12.7 9.0 5.2 1.9 66 20.1 16.2 12.8
3.9 7.8 11 .2 14.9 18.7 22.0 3.7 4 .8 8 .0 11.4 14.7 18.0 20 .3
6.0 3.7 64 19.0 15.8 12.8 9.3 6.1
5.0 8.2 11.2 14.7 17.9 20.3 19.2 16.0 12.6 9.3 8.3 11.4 14.5 17.4 19 .2
62 18.3 15.5 12.7 9.6 6 .7 4 .8 5.6
8.5 11 .3 14.4 17.3 19.2 18.4 15.7 12.6 9.5 6.6 4.8 14.3 16 .9 18.4
5.7 12.6 9.8 7.2 5.6 6 .3 8 .7 11 .5
16.8 18.4 17.7 15.3 12.5 9.7 7.1 5.6 60 17.6 15.2 17 .8
6.4 8.8 11 .4 14.2 7.6 6 .2 6 .8 8 .9 11 .5 14.1 16 .5
15.1 12.5 9.9 7.5 6.2 58 17.1 14.9 12.6 9.9
6.9 9.1 11.4 14.1 16.4 17.8 17.2 7 .2 9 .2 11 .6 13.9 16.1 17.3
7.9 6.7 56 16.7 14.7 12.5 10.1 8.0 6 .7
7.3 9.3 11 .5 13.9 16.0 17.3 16.8 14.8 12.4 10.1 11.6 13.8 15 .8 16.9
54 16.3 14.5 12.5 10.2 8.3 7 .2 7 .6 9.4
9.5 11 .5 13.8 15.7 16.8 16.4 14.6 12.4 10.2 8.2 7.1 15.5 16.5
7.7 12.5 10.4 8.6 7 .5 8.0 9 .6 11.6 13.7
15.4 16.5 16.0 14.4 12.4 10.3 8.5 7.5 52' 16.0 14.3
8.0 9.7 11 .5 13.6 7 .9 8 .3 9 .7 11 .7 13.6 15 .3 16 .1 I
14.3 12.3 10.4 8.7 7.9 50 15.7 14.2 12.4 10.5 8.8
8.3 9.8 11 .6 13.5 15.2 16.1 15.7 9 .9 11 .7 13.4 15 .0 15 .8
10.6 9.0 8.2 48 15.4 14.0 12.4 10 .6 9 .0 8 .2 8 .5
8.6 10.0 11 .6 13.4 15.0 15.8 15.5 14.1 12.3 14 .8 15 .5
15.2 13.9 12.4 10.7 9.2 8.5 8 .8 10.0 11 .7 13.3
8.8 10.1 11 .6 13.3 14.8 15.5 15.2 14.0 12.3 10.7 9.2 8.5 46 1
14.9 13.7 12.4 10.8 9 .4 8.7 9 .0 10.2 11 .7 13 .3 14 .6 I 15 .3
9.1 10.3 11 .6 13.2 14.6 15.3 15.0 13.8 12.3 10.7 9.4 8.7 44
14.7 13.6 12.3 10.8 9.6 9.0 9 .2 10.3 11 .7 13.2 14.4 15 0
9.3 10.4 11.7 13.2 14.4 15.0 14.8 13.7 12.3 10.8 9.6 9.0 42
9.7 9.2 40 14.5 13.5 12.3 10.9 9. 8 9 .2 9.4 10.4 11 .8 13.1 14 3 \ 14 .8
9.5 10.5 11 . 7 13.1 14.2 14.8 14.6 13.6 12.2 10.9
9.4 38 14.4 13.4 12.3 11 .0 9.9 9 .4 9 .6 10.5 11 .8 13 .0 14 .1 1 14 .6 I
9.6 10.6 11 .7 13.0 14.1 14.6 14.4 13.5 12.2 11 .0 9.9
12.2 11 .1 10.1 9.6 36 14.2 13.3 12.3 11 .1 10.1 9.6 9 .8 10.6 11 .8 12.9 13 .9 \ 14.4
9.8 10.7 11 . 7 12.9 13.9 14.4 14.2 13.4
13.3 12.2 11.1 10.2 9.7 34 14.0 13.2 12.2 11.1 10.2 9 .7 9 .9 10.7 11 .8 12 .9 13.8 14 .3
10.0 10.8 11 .8 12.9 13.8 14.3 14.1
13.9 13.2 12.2 11 .2 10.3 9.9 32 13.9 13.1 12.2 11 .2 10.4 9.9 10.1 10.8 11 .8 12.8 13 .7 I 14 .1 '
10.1 10.9 11 .8 12.8 13.6 14.1
12.7 13.5 13.9 13.8 13.1 12.2 11 .3 10.5 10.1 30 13.7 13.0 12.2 11 .3 10.5 10.1 10.2 10.9 11 .8 12 .7 13 .5 \ 13 9 I
10.3 11.0 11 .8
13.4 13.8 13.6 13.0 12.2 11 .3 10.6 10.2 28 13.6 13.0 12.2 11 .3 10.6 10.2 10.4 11 .0 11 .8 12 .7 13.4 13 8
10.4 11 .0 11 .8 12.7
11 .1 11 .8 12.6 13.3 13.6 13.5 12.9 12.1 11.4 10.7 10.4 26 13.5 12.9 12.2 11.4 10.7 10.4 10.5 11.1 11 .9 12 .6 13 .3 13 .6
10.5
10.7 11 .2 11 .8 12.6 13.2 13.5 13.3 12.8 12.1 11.4 10.8 10.5 24 13.3 12.8 12.2 11.4 10 .8 10.5 10.7 11 .2 11 .9 12 .6 13 .2 13 5
10.8 11 .3 11 .9 12.5 13.1 13.3 13.2 12.8 12.1 11 .5 10.9 10.7 22 13.2 12 .7 12. 1 11.5 10.9 10.7 10.8 11 .2 11 .9 12 .5 13 .1 13.3
10.9 11 .3 11 .9 12.5 12.9 13.2 13.1 12.7 12.1 11 .5 11 .0 10.8 20 13.1 12.7 12 .1 11 .5 11 .1 10.8 10.9 11 .3 1 1.9 12 .5 130 13 2
11 .0 11.4 11 .9 12.4 12.8 . 13.1 13.0 . 12.6 12.1 11 .6 11 .1 10.9 18 13.0 12.6 12.1 11 .6 11 .2 10.9 11 .0 11 .4 11 .9 12.4 12 .9 13 1
11 .1 11 .5 11 .9 12.4 12.7 12.9 12.9 12.5 12.1 11 .6 11.2 11.1 16 12.9 12.5 12.1 11.6 11 .3 11.1 11 .1 11 .5 11 .9 12.4 12 .8 12 9
11 .3 11 .6 11 .9 12.3 12.6 12.8 12.8 12.5 12.1 11 .7 11 .3 11 .2 14 12.7 12.4 12.1 11 .7 11 .4 11 .2 11 .2 11 .5 11 .9 12.3 12.7 12 .8
11.4 11 .6 11 .9 12.3 12.6 12.7 12.6 12.4 12.1 11.7 11.4 11.3 12 12.6 12.4 12.1 11 .7 11 .4 11 .3 11 .4 11 .6 11 .9 12 .3 12 .6 12 7
11 .5 11 .7 11 .9 12.2 12.5 12.6 12.5 12.3 12.1 11 .8 11.5 11.4 10 12.5 12.3 12.1 11 .8 11 .5 11 .4 11 .5 11 .7 119 I 122 12 5 12 6
11 .6 11 .7 11 .9 12.2 12.4 12.5 12.4 12.3 12.0 11.8 11 .6 11.5 8 12.4 12.3 12.1 11 .8 11 .6 11 .5 11 .6 11 . 7 12 0 12 2 12 4 12 5
11 .7 11 .8 12.0 12.1 12.3 12.3 12.3 12.2 12.0 11 .9 11 .7 11 .7 6 12.3 12.2 12.0 11 .9 11 . 7 11 . 7 11 .7 11 .8 12 .0 12. 1 12 3 12 3
11.8 11 .9 12.0 12.1 12.2 12.2 12.2 12.1 12.0 11 .9 11.8 11 .8 4 12.2 12. 1 12.0 11 .9 11 .8 11 .8 11 .8 11 .9 12 0 12 1 12 2 1
22
\ 11.9 11 .9 12.0 12.0 12.1 12.1 12.1 12.1 12.0 12.0 11 .9 11 .9 2 12.1 12.1 12.0 12.0 11 .9 11 .9 11 .9 11. 9 12 0 12 . 0 12 ' -42 "
I 12 .0 \ 12.0 \ 12.0 I 12.0 1 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0 0 12.0 12.0 12.0 12 .0 12.0 12.0 12 .0 120 / 120 12 0 f2 0 12:;
'\ \Ja\ues ior N on \hp 1 &;\n r4.-::t.\.l nf lh= m,... ....... h ............ ui.....l. ...... ..... ____ __. _ .. : . .-. -· cN o , 5 '
ag e d o v er all d a ys with in the month . Only fo r h ig h latitude s g r ea te r than 55
dur'mg winter months de\liations may be more than 1 % .