Grand Coulee Daily Outflow in Thousands of CFS for Water Year 2026 Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep 01 48.9 79.7 89.2 --- --- --- --- --- --- --- --- --- 02 59.3 78.1 76.8 --- --- --- --- --- --- --- --- --- 03 51.5 97.6 95.1 --- --- --- --- --- --- --- --- --- 04 42.9 91.3 --- --- --- --- --- --- --- --- --- --- 05 46.8 77.9 --- --- --- --- --- --- --- --- --- --- 06 71.3 72.3 --- --- --- --- --- --- --- --- --- --- 07 69.7 70.9 --- --- --- --- --- --- --- --- --- --- 08 73.2 79.9 --- --- --- --- --- --- --- --- --- --- 09 71.7 69.9 --- --- --- --- --- --- --- --- --- --- 10 55.7 69.2 --- --- --- --- --- --- --- --- --- --- 11 47.9 77.6 --- --- --- --- --- --- --- --- --- --- 12 57.8 81.1 --- --- --- --- --- --- --- --- --- --- 13 75.5 75.8 --- --- --- --- --- --- --- --- --- --- 14 75.3 71.0 --- --- --- --- --- --- --- --- --- --- 15 73.4 72.2 --- --- --- --- --- --- --- --- --- --- 16 67.9 81.7 --- --- --- --- --- --- --- --- --- --- 17 43.8 85.1 --- --- --- --- --- --- --- --- --- --- 18 65.7 99.3 --- --- --- --- --- --- --- --- --- --- 19 46.5 100.1 --- --- --- --- --- --- --- --- --- --- 20 60.6 94.2 --- --- --- --- --- --- --- --- --- --- 21 74.0 92.6 --- --- --- --- --- --- --- --- --- --- 22 66.8 86.3 --- --- --- --- --- --- --- --- --- --- 23 69.9 73.6 --- --- --- --- --- --- --- --- --- --- 24 75.9 91.0 --- --- --- --- --- --- --- --- --- --- 25 56.9 102.1 --- --- --- --- --- --- --- --- --- --- 26 50.9 78.3 --- --- --- --- --- --- --- --- --- --- 27 62.7 65.3 --- --- --- --- --- --- --- --- --- --- 28 67.1 68.2 --- --- --- --- --- --- --- --- --- --- 29 53.1 97.5 --- --- --- --- --- --- --- --- --- 30 73.1 93.6 --- --- --- --- --- --- --- --- --- 31 80.8 --- --- --- --- --- --- --- ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ VOL 3841 4906 518