| Minimum |
| January |
31 |
1947 |
-52.2 |
| February |
2 |
1968 |
-51.2 |
| March |
8 |
1972 |
-40.6 |
| April |
10 |
1986 |
-29.4 |
| May |
10 |
1964 |
-11.7 |
| June |
3 |
1971 |
-2.8 |
| July |
19 |
1984 |
-0.5 |
| August |
25 |
1948 |
-4.4 |
| September |
27 |
1983 |
-19.4 |
| October |
28 |
1982 |
-31.1 |
| November |
27 |
1948 |
-40.6 |
| December |
19 |
1942 |
-47.8 |
|
| Maximum |
| January |
26 |
1977 |
9.0 |
| February |
27 |
1968 |
11.7 |
| March |
22 |
1979 |
11.7 |
| April |
27 |
1958 |
20.6 |
| May |
30 |
1983 |
34.1 |
| June |
14 |
1969 |
34.4 |
| July |
9 |
1951 |
32.8 |
| August |
5 |
1999 |
31.6 |
| September |
3 |
1942 |
26.7 |
| October |
1 |
1958 |
18.9 |
| November |
2 |
1970 |
11.7 |
| December |
10 |
1986 |
9.5 |
|