ILLINOIS CLIMATE
Probability of last spring freeze (32° or lower) after date shown by
districts
| Probability
|
NW |
NE* |
W |
C |
E |
WSW |
ESE |
SW |
SE |
| 3 years in 4 |
Apr. 21 |
Apr. 19 |
Apr. 13 |
Apr. 16 |
Apr. 16 |
Apr. 10 |
Apr. 11 |
Apr. 2 |
Apr. 3 |
| 1 year in 2 |
Apr. 30 |
Apr. 28 |
Apr. 22 |
Apr. 25 |
Apr. 25 |
Apr. 19 |
Apr. 20 |
Apr. 11 |
Apr. 12 |
| 1 year in 4 |
May 9 |
May 7 |
May 1 |
May 4 |
May 4 |
Apr. 28 |
Apr. 29 |
Apr. 20 |
Apr. 21 |
| 1 year in 10 |
May 17 |
May 15 |
May 9 |
May 12 |
May 12 |
May 6 |
May 7 |
Apr. 28 |
Apr. 29 |
| 1 year in 20 |
May 22 |
May 20 |
May 14 |
May 17 |
May 17 |
May 11 |
May 12 |
May 3 |
May 4 |
* Last spring freeze averages approximately ten days earlier in Cook County
near Lake Michigan.
Source: Illinois State Water Survey.
Probability of first fall freeze (32° or lower) before date shown by
districts
| Probability |
NW |
NE* |
W |
C |
E |
WSW |
ESE |
SW |
SE |
| 3 years in 4 |
Oct. 17 |
Oct. 18 |
Oct. 25 |
Oct. 26 |
Oct. 25 |
Oct. 28 |
Oct. 28 |
Nov. 3 |
Nov. 4 |
| 1 year in 2 |
Oct. 8 |
Oct. 9 |
Oct. 16 |
Oct. 17 |
Oct. 16 |
Oct. 19 |
Oct. 19 |
Oct. 25 |
Oct. 26 |
| 1 year in 4 |
Sep. 29 |
Sep. 30 |
Oct. 7 |
Oct. 8 |
Oct. 7 |
Oct. 10 |
Oct. 10 |
Oct. 16 |
Oct. 17 |
| 1 year in 10 |
Sep. 22 |
Sep. 23 |
Sep. 30 |
Oct. 1 |
Sep. 30 |
Oct. 3 |
Oct. 3 |
Oct. 9 |
Oct. 10 |
| 1 year in 20 |
Sep. 17 |
Sep. 18 |
Sep. 25 |
Sep. 26 |
Sep. 25 |
Sep. 28 |
Sep. 28 |
Oct. 4 |
Oct. 5 |
*First fall freeze averages approximately ten days later in Cook County near
Lake Michigan.
Source: Illinois State Water Survey
MONTHLY PRECIPITATION: Avg. number of inches and departures from long term
means by districts, 1998
Month |
NW |
NE |
W |
C |
E |
WSW |
ESE |
SW |
SE |
| Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
| Jan |
2.47 |
1.40 |
3.03 |
1.46 |
2.12 |
0.67 |
2.85 |
1.28 |
2.59 |
0.94 |
2.66 |
0.99 |
2.83 |
0.80 |
2.95 |
0.59 |
3.26 |
0.57 |
| Feb. |
2.44 |
1.30 |
1.87 |
0.54 |
3.32 |
1.91 |
2.52 |
1.11 |
1.84 |
0.21 |
2.76 |
0.89 |
2.18 |
-0.03 |
3.39 |
0.60 |
3.15 |
0.10 |
| Mar |
4.38 |
1.78 |
3.25 |
0.57 |
4.85 |
1.76 |
4.72 |
1.64 |
5.30 |
2.31 |
4.88 |
1.50 |
4.89 |
1.15 |
5.26 |
0.93 |
3.50 |
-1.25 |
| April |
5.04 |
1.36 |
4.03 |
0.30 |
4.62 |
0.86 |
4.42 |
0.67 |
4.08 |
0.30 |
4.45 |
0.76 |
5.37 |
1.54 |
5.34 |
1.41 |
7.58 |
3.19 |
| May |
3.41 |
-0.47 |
4.13 |
0.49 |
5.18 |
1.08 |
5.56 |
1.58 |
5.65 |
1.65 |
4.89 |
0.61 |
5.75 |
1.52 |
3.93 |
-0.51 |
4.74 |
-0.15 |
| June |
6.88 |
2.70 |
5.70 |
1.65 |
7.57 |
3.59 |
7.24 |
3.42 |
8.29 |
4.44 |
8.81 |
5.09 |
7.88 |
4.07 |
9.18 |
5.44 |
7.76 |
3.90 |
| July |
2.59 |
-1.40 |
2.49 |
-1.49 |
2.47 |
-1.92 |
2.44 |
-1.51 |
4.61 |
0.40 |
2.71 |
-1.20 |
4.38 |
0.15 |
5.56 |
1.71 |
4.30 |
0.25 |
| Aug |
4.63 |
0.55 |
3.92 |
-0.04 |
2.90 |
-0.84 |
3.57 |
0.12 |
2.00 |
-1.63 |
2.30 |
-1.14 |
3.37 |
0.01 |
3.32 |
-0.19 |
3.03 |
-0.34 |
| Sept. |
3.61 |
-0.26 |
2.48 |
-1.31 |
4.55 |
0.27 |
1.48 |
-2.27 |
1.13 |
-2.28 |
2.71 |
-0.79 |
2.01 |
-1.14 |
1.27 |
-2.01 |
1.42 |
-1.66 |
| Oct. |
6.77 |
4.02 |
5.02 |
2.52 |
5.50 |
2.49 |
3.66 |
0.94 |
3.01 |
0.37 |
3.43 |
0.61 |
3.40 |
0.54 |
3.71 |
0.75 |
4.49 |
1.48 |
| Nov. |
2.22 |
-2.70 |
1.72 |
-1.11 |
3.60 |
0.97 |
1.8 |
-0.93 |
1.70 |
-1.21 |
3.21 |
0.15 |
3.17 |
-0.33 |
2.39 |
-1.45 |
2.38 |
-1.63 |
| Dec. |
1.22 |
-0.82 |
1.54 |
-0.84 |
1.96 |
-0.32 |
1.38 |
-1.30 |
1.56 |
-1.22 |
0.93 |
-2.02 |
1.41 |
-2.01 |
2.31 |
-1.46 |
3.22 |
-0.83 |
| Annual |
45.66 |
9.63 |
39.18 |
2.74 |
48.64 |
10.52 |
41.78 |
4.75 |
41.76 |
4.28 |
43.68 |
5.45 |
46.64 |
6.27 |
48.61 |
5.81 |
48.83 |
3.63 |
Source: National Weather Service
MONTHLY TEMPERATURES: Average temperature and departures from long term
means by district, 1998
Month |
NW |
NE |
W |
C |
E |
WSW |
ESE |
SW |
SE |
| Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
Prec. |
Dep. |
| Jan. |
26.2 |
7.0 |
28.0 |
7.3 |
28.8 |
5.6 |
30.1 |
7.1 |
30.4 |
7.4 |
32.5 |
6.6 |
34.8 |
8.1 |
37.4 |
7.1 |
38.2 |
7.6 |
| Feb. |
36.7 |
12.7 |
37.8 |
12.6 |
38.6 |
10.6 |
39.1 |
11.5 |
38.7 |
11.4 |
40.5 |
10.1 |
41.0 |
9.8 |
43.0 |
8.3 |
42.5 |
7.5 |
| March |
36.7 |
1.2 |
38.1 |
1.4 |
38.5 |
-1.5 |
39.5 |
-0.3 |
38.8 |
-0.6 |
40.5 |
-1.6 |
42.0 |
-0.8 |
44.7 |
-1.0 |
45.3 |
-0.7 |
| April |
49.9 |
0.5 |
49.8 |
1.1 |
51.8 |
-0.8 |
52.0 |
-0.2 |
52.0 |
0.7 |
53.2 |
-1.0 |
53.9 |
-0.4 |
55.8 |
-0.9 |
55.8 |
-0.9 |
| May |
65.4 |
4.8 |
64.9 |
5.3 |
67.0 |
4.2 |
66.9 |
4.3 |
66.6 |
4.5 |
68.4 |
4.5 |
68.2 |
4.1 |
70.4 |
4.7 |
69.6 |
3.9 |
| June |
68.8 |
-1.1 |
69.2 |
-0.1 |
70.9 |
-1.1 |
70.9 |
-1.0 |
70.9 |
-0.6 |
72.6 |
-0.2 |
73.2 |
0.2 |
75.4 |
1.1 |
75.6 |
1.4 |
| July |
73.3 |
-0.5 |
75.7 |
0.2 |
75.9 |
-0.2 |
75.3 |
0.0 |
73.8 |
-0.9 |
76.5 |
-0.1 |
76.3 |
-0.2 |
78.4 |
0.3 |
78.1 |
0.2 |
| August |
73.2 |
1.8 |
73.7 |
2.1 |
75.3 |
1.9 |
74.8 |
1.8 |
73.8 |
1.5 |
75.9 |
1.8 |
75.6 |
1.3 |
77.3 |
1.3 |
76.6 |
0.6 |
| Sept. |
67.8 |
4.0 |
68.6 |
4.2 |
70.7 |
4.4 |
70.8 |
4.5 |
70.5 |
4.5 |
72.1 |
4.4 |
72.3 |
4.4 |
74.0 |
4.7 |
74.0 |
4.5 |
| Oct. |
53.6 |
1.3 |
54.6 |
1.7 |
55.6 |
0.7 |
55.6 |
1.1 |
55.5 |
1.5 |
57.3 |
1.3 |
58.3 |
2.2 |
60.7 |
2.7 |
60.5 |
2.6 |
| Nov. |
42.6 |
3.7 |
43.8 |
3.7 |
44.7 |
2.9 |
45.0 |
3.3 |
44.3 |
2.7 |
46.4 |
2.7 |
46.5 |
2.3 |
49.3 |
2.8 |
49.3 |
2.5 |
| Dec. |
32.6 |
7.8 |
34.1 |
7.6 |
33.7 |
5.5 |
34.3 |
6.0 |
34.7 |
6.2 |
35.5 |
4.5 |
36.5 |
4.6 |
38.3 |
3.4 |
38.5 |
3.1 |
| Annual |
52.3 |
3.6 |
53.0 |
3.9 |
54.3 |
2.7 |
54.5 |
3.2 |
54.2 |
3.2 |
56.0 |
2.8 |
56.6 |
3.0 |
58.7 |
2.9 |
58.7 |
2.7 |
Source: National Weather Service
Illinois Agricultural Statistics Service
Annual Summary - 1999 |
Page 15 |
|
