The Northern Pike is a cold water fish. Although the record highs are the same, there is a 20 degree difference in average high temperatures. This is significant when talking about water temperature.
The average number of days above 90 F for New Orleans is 71 days. While the average number of days above 90 F for Rockford, IL is 15 days. So there is a nearly a two month difference of when New Orleans has a high above 90 F and Rockford, IL does. New Orleans also has, on average, 277 days or 76% of the year above 70 F. Rockford, IL has an average of 165 days or 45% of the year above 65 F.
Also, New Orleans has an average of six nights where the temperature drops to 32 F or lower and nine days a year the temperature fails to make it above 49 F. Whereas Rockford, IL has an average of 145 days below 32 F with 26 of these days being below 5 F.
While the record high temperatures look similar, you need a more detailed breakdown to determine water temperatures. The breakdown I have provided shows why there would be a significant difference in water temperature readings. It is easy for one day to have spikes or declines in temperature but water temperatures do not change instantly. A small pond would change the fastest while a larger lake such as this one would take more time.
My fear is that the year around water temperature would not be suitable to northern pike. There would be trouble locating a hatchery with northern pike in the southern U.S.
Northern pike have been introduced to some south states but if you look closely at the breakdown the pike were introduced in the cooler waters of the southern states and introduced by state agencies.
If you go here:
http://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=676. You can see that there are no northern pike in the states of Louisanna, Mississippi, Alabama, or Florida. All the previously listed states have several things in common: All border the Gulf of Mexico, elevation wise are fairly low states and have similar climates.
