Apr. 15, 1925 
Use of Liability Ratings in Forest Fire Protection 
751 
Table XIII. — Average number of general risk fires per year, per million acres , by 
10-day periods —Continued 
REGION 17-SOUTHERN CALIFORNIA 
Number of fires, by forest types 
Periods 
» 
Western 
yellow 
and 
Jeffrey 
pines 
Fir and 
pine 
slopes 
Hardwood 
bottoms 
Chaparral 
Grass and 
sage d 
Jan. 1-10__ 
0.6 
0.2 
11-20_ . 
5. O 
21-31. 
1 
. 1 
Feb. 1-10_ 
. 1 
11-20_ 
. 1 
21-28/29 
' 
.3 
Mar. 1-10. 
11-20- 
i 
. 1 
21-31_ 
i 
1.4 
. 1 
5.0 
Apr. 1-10 
. 1 
11-20 
0. 6 
. 1 
21-30 
.2 
May 1-10 
1.8 
.3 
5.6 
11-20..- 
.6 
2.8 
. 1 
21-31.. 
2.4 
1.4 
.2 
10.6 
June 1-10___ _ 
1.2 
2.8 
.2 
5.0 
11-20-.- 
1.8 
7.0 
.9 
45.0 
21-30_ 
2.4 
5.4 
12.6 
.8 
25.0 
July 1-10_ 
1.8 
1.8 
14.0 
1.5 
20.0 
11-20_ 
5.4 
1.8 
5.6 
1.5 
15.0 
21-31_ 
6.0 
3.6 
2.8 
3.2 
50.0 
Aug. 1-10__ 
10.8 
5.4 
9.8 
2.6 
5.0 
11-20_ 
6.0 
5.4 
23.8 
2.7 
15.0 
21-31_ 
9.0 
18.0 
21.0 
2.8 
20.0 
Sept. 1-10_ 
4.8 
12.6 
22.4 
1.7 
25.0 
11-20_ 
7.8 
7.2 
5.6 
2.0 
20.0 
21-30_ 
1.8 
1.8 
1.4 
2.0 
5.0 
Oct. 1-10_ 
1.8 
1.4 
1.0 
15.0 
11-20- 
.6 
2.8 
2.1 
15.0 
21-31_ 
1.8 
1.8 
4.2 
1.0 
25.0 
Nov. 1-10. 
1 . 2 
2.8 
.8 
20.0 
11-20_ 
1.2 
3.6 
2.8 
.7 
10.0 
21-30. 
1 . 2 
1.4 
1.3 
5.0 
Dec. 1-10 
.4 
11-20. 
.1 
21-31_ 
. 1 
5.6 
Danger periods A b _ 
May 21- 
May 1-10; 
Mar. 21- 
July 1-Oct. 
Jan. 11-20; 
Oct. 10; 
June*21- 
31; May 
31; Nov. 
Mar. 21- 
Oct. 21- 
Sept. 30; 
11-Nov. 
21-30 
31; May 
Nov. 30. 
Oct. 21- 
30. 
1-No v. 
31; Nov. 
30; Dec. 
11-20. 
21-31. 
Danger periods B 6 _ 
July 11- 
June 21-30; 
June 11- 
July 21-31. 
Same as A 
Sept. 20. 
July 21- 
Sept. 20; 
Sept. 20; 
Oct. 21- 
Nov. 11- 
31. 
20. 
6 Danger periods A are the periods during which one or more than one fire occurs in 10 days. Danger 
periods B are the periods within which three or more fires occur in 10 days, or two fires or more a week. 
d Data on area very unsatisfactory, figures probably too high. 
