Mississippi River North Temperature

Section 303 Section 303.331  Mississippi River North Temperature Instead of the standards of 35 Ill. Adm. Code 302.211(e) the water temperature at representative locations in the main river of the Mississippi River from the Wisconsin border to the Rock River must not exceed the maximum limits in the following table during more than 1% of the hours in the 12-month period ending with any month.  The water temperature at these locations must not at any time exceed the maximum limits in the following table by more than 1.7 ºC (3 ºF). ºC ºF ºC ºF JAN. 7 45 JUL. 30 86 FEB. 7 45 AUG. 30 86 MAR. 14 57 SEPT. 29 85 APR. 20 68 OCT. 24 75 MAY 26 78 NOV. 18 65 JUN. 29 85 DEC. 11 52