404 
The Ohio Naturalist. 
[Vol. III, No. 6, 
the prevailing direction has been south-east, so that there is no 
very decisive evidence in favor of any particular direction. 
Cleveland shows a prevailing south-east wind, but Pittsburg is 
decidedly a station of north-west winds. 
For most of the stations the windiest month of the 3’ear is 
March, and the calmest month August, although Cleveland’s 
highest winds are in November. In the course of the year there 
are some interesting variations in wind direction at some of the 
stations, as the table below will show. At the three lake stations 
the wind seems to show during the earlier part of the year a ten- 
dency to veer to a more westerly direction than is taken during 
the later months. 
WIND, DIRECTION AND VELOCITY. 
Stations. 
05 
xS 
a; 
X 
a 
April. 
May. 
June. 
. 
X 
to 
< 
37 
C/2 
u 
0 
0 
£ 
d 
u 
Q 
Mean for 
the year. 
Cincinnati 
1 Prevailing direction, 
’ 1 Miles per hour 
S W 
8.7 
11 w 
9.2 
n w 
9-3 
s e 
8-4 
se 
6-3 
s w 
6.4 
n e 
5-7 
s e 
6 2 
s e 
6.4 
s e 
S . 2 
s e 
8.3 
s e 
7-5 
Columbus . 
( Prevailing direction, 
( Miles per hour 
s w 
9.0 
w 
9 8 
w 
9-9 
n w 
9.2 
s w 
7 5 
s w 
69 
s w 
65 
s w 
6.0 
n w 
6.6 
s e 
7 -i 
s w 
8.6 
s w 
9-8 
s w 
8.1 
Cleveland . 
f Prevailing direction, 
' \ Miles per hour 
s w 
15.6 
s w 
154 
w 
152 
s e 
13 4 
s e 
12.5 
s e 
11. 0 
s e 
10 9 
s e 
10.6 
s e 
13 0 
s e 
14. 1 
s e 
16.8 
s w 
16*1 
s e 
13-7 
Toledo 
( Prevailing direction, 
( Miles per hour 
w 
II . I 
w 
”4 
w 
11 6 
11 w 
11. 4 
w 
9.8 
w 
8.3 
s w 
8.7 
s w 
7-7 
s w 
8.7 
s w 
9-3 
s w 
II.I 
s w 
10.9 
s w 
10. 0 
Pittsburg. 
( Prevailing direction, 
1 Miles per hour 
n w 
7.6 
n w 
7-9 
n w 
7.6 
n w 
6.9 
n w 
6.0 
n w 
5-6 
n w 
5.2 
11 w 
4 8 
n w 
5-5 
n w 
6 7 
n w 
7 -i 
11 w 
7 -i 
n w 
6 -S 
Sandusky . 
( Prevailing direction, 
( Miles per hour 
s w 
9 4 
w 
9.7 
s w 
10.3 
e 
9 4 
s w 
8.6 
s w 
7-4 
s w 
7.2 
n e 
6.9 
s w 
7 6 
s w 
7 8 
s w 
9.8 
s w 
9.3 
s w 
8.6 
KILLING FROST, — DATE OF FIRST AND LAST. 
The date of the last killing frost in the spring and the first one 
in the fall, is perhaps to be ranked as one of the most determina- 
tive factors in ecology, since upon it depends in a measure the 
length of the growing season. 
The data used in this compilation cover a period of ten years 
for most of the stations, although many of these have only partial 
records for the earlier years. Records from twenty-eight stations 
throughout the State were used, but the results are so conflicting 
that only a few general conclusions can now be stated. 
In a general way the immediate Ohio valley shows a longer 
growing season than the central part of the State, but about the 
same length of season as the region immediately adjoining the 
lake. Sandusky, with a growing season of 201 days, and Mari- 
etta, with 186 days, stand at one extreme, while Hillhouse (Lake 
county), with 131 days, and Bowling Green and Defiance, each 
with 14 1 days, stand at the other extreme. 
