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 89.2 131.0 106.5 --- 114.9 160.0 166.5 --- --- --- 02 59.3 78.1 76.8 123.8 124.5 101.3 95.0 130.4 168.5 --- --- --- 03 51.5 97.6 95.1 120.3 120.4 117.4 108.5 127.0 170.9 --- --- --- 04 42.9 91.3 102.7 102.1 105.1 117.9 109.2 143.0 166.9 --- --- --- 05 46.8 77.9 117.2 134.1 113.6 124.5 104.1 136.4 158.6 --- --- --- 06 71.3 72.3 101.6 147.3 117.8 125.1 105.1 93.5 156.3 --- --- --- 07 69.7 70.9 96.4 146.0 106.2 102.1 85.6 97.1 141.0 --- --- --- 08 73.2 79.9 94.1 139.6 113.4 106.2 99.7 106.5 154.9 --- --- --- 09 71.7 69.9 69.7 136.3 124.7 127.4 95.6 123.1 116.4 --- --- --- 10 55.7 69.2 59.7 133.8 127.4 125.5 112.2 116.4 115.8 --- --- --- 11 47.9 77.6 62.9 144.3 118.2 127.8 113.6 124.5 120.0 --- --- --- 12 57.8 81.1 60.2 137.8 123.0 122.7 129.4 137.7 138.2 --- --- --- 13 75.5 75.8 68.9 137.5 122.9 138.7 106.8 111.9 143.2 --- --- --- 14 75.3 71.0 89.8 147.2 111.3 111.7 109.7 123.7 150.3 --- --- --- 15 73.4 72.2 89.8 140.8 112.6 119.0 107.5 123.2 151.8 --- --- --- 16 67.9 81.7 97.1 147.1 143.6 108.6 101.3 113.0 124.0 --- --- --- 17 43.8 85.1 114.8 140.7 131.5 106.1 119.8 109.0 --- --- --- --- 18 65.7 99.3 101.5 146.9 130.8 104.4 96.8 137.1 --- --- --- --- 19 46.5 100.1 88.9 142.8 135.7 114.1 140.2 143.7 --- --- --- --- 20 60.6 94.2 112.0 140.8 151.0 121.9 132.6 131.5 115.8 --- --- --- 21 74.0 92.6 113.1 140.1 139.6 108.5 110.8 125.1 --- --- --- --- 22 66.8 86.3 123.9 131.9 149.9 127.4 111.8 126.5 --- --- --- --- 23 69.9 73.6 135.2 135.3 146.2 135.9 119.8 102.7 --- --- --- --- 24 75.9 91.0 124.1 142.4 142.0 115.6 125.9 103.0 --- --- --- --- 25 56.9 102.1 109.4 134.8 131.9 129.6 129.2 110.8 --- --- --- --- 26 50.9 78.3 124.0 138.0 123.9 132.2 114.8 119.6 --- --- --- --- 27 62.7 65.3 121.4 131.3 118.1 147.4 112.7 117.0 --- --- --- --- 28 67.1 68.2 121.0 121.4 130.0 114.5 129.6 147.4 --- --- --- --- 29 53.1 97.5 120.8 130.1 114.2 146.4 108.1 --- --- --- --- 30 73.1 93.6 136.1 128.4 132.2 133.2 114.0 --- --- --- --- 31 80.8 127.4 111.3 129.5 131.1 --- --- --- ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ VOL 3841 4906 6238 8301 6985 7159 6787 7525 4878