- The average ice out date is April 29th.
- The average ice-out date has varied by decades:
| 1920's |
May 2 |
| 1930's |
April 28 |
| 1940's |
April 25 |
| 1950's |
May 2 |
| 1960's |
May 2 |
| 1970's |
May 2 |
| 1980's |
April 26 |
| 1990's |
April 29 |
- The earliest ice-out was April 10, 1945. The latest was May 23, 1950.
- The ice has never gone out on April 15th. (Too taxing!)
- The percentage of time the ice goes out between the following dates:
| 24% -- April 27 - May 1 |
| 42% -- April 25 - May 3 |
| 56% -- April 23 - May 5 |
| 69% -- April 21 - May 7 |
| 80% -- April 19 - May 9 |
| 88% -- April 17 - May 11 |
| 92% -- April 15 - May 13 |
| 95% -- April 13 - May 15 |
| 97% -- April 11 - May 17 |
- The National Climatic Data Center and international standards require that
climate "normals" (averages) be based on 30 year records. Thus, the "normals"
from 1961 to 1990 are updated for years 1971 to 2000. The following table
indicates "ice-out" trends using this standard on "ice-out" dates:
| Years |
Ave. Ice-Out Date |
Earlier/Later* |
By Time** |
| 1923-1950 |
April 29 |
na |
na |
| 1931-1960 |
April 28 |
Earlier |
2 hr. 3 min. |
| 1941-1970 |
April 30 |
Later |
32 hr. 0 min. |
| 1951-1980 |
April 30 |
Later |
19 hr. 12 min |
| 1961-1990 |
April 29 |
Earlier |
32 hr. 0 min. |
| 1971-2000 |
April 28 |
Earlier |
27 hr. 12 min. |
| * Earlier or later than previous 'ice-out' period. |
| ** Earlier or later by time from previous period (these times are relative,
not absolute 'ice-out' times, and are presented for comparison purposes
only. The average 'ice-out' time for all recorded years is 1 hour, 53 min.
into the April 29th 24 hour clock |
|
