Ten driest years
Ranking of dry year 
Standardized 
deviation 
of rainfall 
Tropical 
Storms 
only 
Minor 
hurricanes 
(Cat. 1-2) 
Intense 
hurricanes 
(Cat.3-5) 
Intense-hurricane 
days 
1984 (extremely dry) 
-0.72 
7 
4 
1 
0.75 
1983
-0.72 
1 
2 
1 
0.25 
1977
-0.72 
1 
4 
1 
1.00 
1972
-0.64 
1 
3 
0 
0.00 
1973
-0.61 
3 
3 
1 
0.25 
1986
-0.56 
2 
4 
0 
0.00 
1982
-0.54 
3 
1 
1 
1.25 
1987
-0.50 
4 
2 
1 
0.50 
1976
-0.48 
2 
4 
2 
1.00 
1980 (moderately dry) 
-0.46 
2 
7 
2 
7.25 
Mean
-0.64 
2.6 
3.4 
1.0 
1.23 
Ten Wettest years
Ranking of dry year 
Standardized 
deviation 
of rainfall 
Tropical 
Storms 
only 
Minor 
hurricanes 
(Cat. 1-2) 
Intense 
hurricanes 
(Cat.3-5) 
Intense-hurricane 
days 
1955 (extremely wet)
1.20 
3 
3 
6 
17.25 
1964
1.00
6
0
6
14.75
1961
0.94
3
1
7
24.50
1969
0.78
5
7
5
6.75
1953
0.73
8
2
4
6.75
1989
0.71
4
5
2
10.75
1952
0.62
1
3
3
6.75
1950
0.57
2
3
8
18.75
1958
0.55
3
2
5
9.50
1960 (moderately wet)
0.55
3
2
2
11.00
___
_
_
_
_____
Mean
0.76
3.8
2.8
4.8
12.72
Ratio wet/dry
1.5/1
0.8/1
4.8/1
10.3/1

Table 3. Comparison of the early-season (i.e., prior to 1 August) West African rainfall index for the ten driest and ten wettest seasons during 1949-1990 versus the number of tropical storms (weaker than hurricane force), minor (category 1 or 2) hurricanes, intense (category 3-5) hurricanes, and intense-hurricane days. Early season rainfall includes Gulf of Guinea rainfall for August through November during the previous year (weighted 0.3) and current year June-July western Sahel region rainfall (weighted 0.7).