King salmon fishing is a "visual thing" in that angler success appears to be directly related to the water quality and visibility in the river. Fish striking a lure are reacting from a visual cue which induces the strike. If they can't see it, they can't hit it. Even adding bait or scent adds little to the success rate when water quality is poor.
Visibility: Readings below 20 inches make fish catching very tough. A few fish are caught but one fish per half dozen boats (4 anglers each) is not a good day for the private angler to give it a try. For our latest river conditions, clarity reaching the upper 20's provides good conditions to get out and give it a try. It can drop 10 inches overnight and take days to recover. Any day of July has enough fish present to make it worth trying; but you must roll with the conditions offering the best shot. 30 inches and above are very good conditions nowdays and if the temperature cooperates, you're half way there.
Temperature: Below 50's seems to be making the kings sluggish in their desire to bite. Some still bite but this range appears to be a negative factor at these temperatures. The entire 50's range "appears" to be ideal. Enough warmth for the fish to be active and aggressive. And the best catches have been made in this range. 60 degrees and above...fish appear stressed from thermal shock when entering from the cooler saltwater. Expect the bite, no matter what the count numbers are, to be affected. Slow changes into this range aren't as bad as fast changes. But beware, when the temperature gets too high, a hard rain or high winds at the lake can drop the river 7-8 degrees. Experience shows 4-5 degree temperature swings in a day also knock the fish off the bite....often for several days following! This may be the reason the last couple of years have always had a better bite early in the morning than in the afternoon when the temperature goes up.
Those anglers who fish the river frequently should begin keeping a diary or record of their outings and their success. These conditions aren't going away for a few more years. Compare your success and what you observe on the river each day you are out there with the data we provide. It will make you one of the more knowledgeable anglers on the river. Its not all technique or luck anymore. The early bird gets the fish nowdays.
For those who occasionally fish the river or make one or two journeys down from Anchorage each year, your best bet is to monitor AOJ and make some educated decisions on when to come. But remember, there is only a limited number of days in July for fishing kings and a day on the water beats sitting at home anytime. Good Luck and Good Fishing!