Lake Ontario Outflow Changes
Outflows from Lake Ontario are established by the International Lake Ontario - St. Lawrence River Board in accordance with the current regulation plan and the International Joint Commission's Orders of Approval. The table below and the CSV file above display the outflow changes that have occurred this year. All flows are reported in cubic metres and cubic feet per second.
| DATE | HOUR/HEURE | OUTFLOW/DÉBIT | OUTFLOW/DÉBIT |
| (YYYY-MM-DD) | (HHMM) | (m3/s) | (cfs) |
| 2021-07-31 | 0001 | 8,100 | 286,000 |
| 2021-07-24 | 0001 | 8,140 | 287,500 |
| 2021-07-17 | 0001 | 7,960 | 281,100 |
| 2021-07-10 | 0001 | 7,620 | 269,100 |
| 2021-07-03 | 0001 | 7,600 | 268,400 |
| 2021-06-26 | 0001 | 7,550 | 266,600 |
| 2021-06-19 | 0001 | 7,560 | 267,000 |
| 2021-06-12 | 0001 | 7,600 | 268,400 |
| 2021-06-05 | 0001 | 7,620 | 269,100 |
| 2021-05-29 | 0001 | 7,840 | 276,900 |
| 2021-05-22 | 0001 | 7,970 | 281,500 |
| 2021-05-15 | 0001 | 8,090 | 285,700 |
| 2021-05-08 | 0001 | 8,070 | 285,000 |
| 2021-05-01 | 0001 | 7,920 | 279,700 |
| 2021-04-24 | 0001 | 7,410 | 261,700 |
| 2021-04-16 | 2101 | 7,350 | 259,600 |
| 2021-04-15 | 2101 | 7,820 | 276,200 |
| 2021-04-10 | 0001 | 7,420 | 262,000 |
| 2021-04-03 | 0001 | 7,980 | 281,800 |
| 2021-03-20 | 0001 | 7,380 | 260,600 |
| 2021-03-13 | 0001 | 8,000 | 282,500 |
| 2021-03-06 | 0001 | 8,080 | 285,300 |
| 2021-03-01 | 0001 | 8,140 | 287,500 |
| 2021-02-21 | 1501 | 8,600 | 303,700 |
| 2021-02-20 | 1201 | 8,400 | 296,600 |
| 2021-02-19 | 1201 | 8,000 | 282,500 |
| 2021-02-18 | 1801 | 7,600 | 268,400 |
| 2021-02-18 | 0701 | 7,400 | 261,300 |
| 2021-02-17 | 1101 | 7,000 | 247,200 |
| 2021-02-16 | 1401 | 6,600 | 233,100 |
| 2021-02-12 | 1401 | 7,000 | 247,200 |
| 2021-02-11 | 1601 | 7,400 | 261,300 |
| 2021-02-10 | 1901 | 8,300 | 293,100 |
| 2021-02-09 | 2001 | 8,500 | 300,200 |
| 2021-02-05 | 1801 | 8,800 | 310,800 |
| 2021-02-04 | 1201 | 8,200 | 289,600 |
| 2021-02-03 | 1401 | 7,700 | 271,900 |
| 2021-02-01 | 1501 | 7,100 | 250,700 |
| 2021-01-31 | 1801 | 6,900 | 243,700 |
| 2021-01-28 | 1601 | 7,200 | 254,300 |
| 2021-01-26 | 1001 | 7,700 | 271,900 |
| 2021-01-24 | 1701 | 7,200 | 254,300 |
| 2021-01-23 | 1701 | 8,400 | 296,600 |
| 2021-01-19 | 1501 | 9,200 | 324,900 |
| 2021-01-16 | 1701 | 9,400 | 332,000 |
| 2021-01-14 | 1201 | 9,200 | 324,900 |
| 2021-01-12 | 1201 | 9,500 | 335,500 |
| 2021-01-09 | 1501 | 9,400 | 332,000 |
| 2021-01-07 | 1301 | 9,300 | 328,400 |
| 2021-01-05 | 1001 | 9,200 | 324,900 |
| 2021-01-04 | 1701 | 9,400 | 332,000 |
| 2021-01-03 | 1301 | 9,500 | 335,500 |
| 2021-01-01 | 0801 | 9,400 | 332,000 |
| 2020-12-26 | 0001 | 8,090 | 285,700 |
To view outflow change records from previous years, please use the links below: