Posted on May 28 2019
Without stirring up controversy I'd like to share my personal observations on how sunshine or lack thereof affects fishing. Specifically, sunshiney days vs cloudy days. Far to often lately I've read about how it's going to be a good fishing day because the weatherman is predicting clouds and rain instead of those awful sunny days. It's just not that simple.
Let's take it by seasons:
Springtime - The water is cold. Hendricksons need the water to warm up to almost 50 degrees to hatch. Sunshine is almost a requirement for early season Hendrickson hatches. The Hendrickson hatches move up stream as the water warms. At present they are in the upper part of both branches where the release water comes out of the reservoir at about 44 degrees. Without sunshine (like today) the water doesn't get warm enough where the hatch is occuring to allow the bugs to hatch. Caddis (the other early season bug) love sunshine. If it's warm and sunny they hatch in the morning and lay their eggs in the evening, thus extending the hours available for fishing to feeding trout. If it's cloudy, cold and rainy the caddis are no shows at both ends of the day. From my experience it's far better to have warm sunny days in the spring months.
Summer - Now the pendulum swings at least part way. The upper portions of both branches have summer sulfurs that hatch at about 52 degrees. With the thermocline in place, the water coming out of the reservoirs at 44 degrees still needs to be warmed up by sunshine to get optimal sulfur hatches. On the other hand, no one wants to journey down the Big River on a bright sunny July day. The water is too warm for summer bugs to hatch until late evening and often gets too warm to even fish for trout (over 70 degrees). Fish don't really like bright sun. You may have noticed that on a partly cloudy day like Monday, with the water covered with bugs, there were far more fish rising when a cloud covered the sun than when the sun shone brightly. Cloudy rainy days in the summertime allow the water to cool which lets it hold more oxygen which serves to invigorate the trout. They also promote daytime olive hatches (not sure if less light or cooler temps or both are required)
Fall - It gets more complicated. Pseudos, the main fall fly, often hatch in the most miserable cold, rainy and windy weather. But they hatch during the heat of the day ( from 2:00 to 5:00). Not sure what to root for here.
Today - The morning drizzle wiped out both the early caddis hatch and morning spinners. Lack of sun kept the water (where I was) too cold for a good hatch of any kind and the thunderstorms ended the mid afternoon Hendrickson spinners and evening caddis spinners almost before they got started
Let's take it by seasons:
Springtime - The water is cold. Hendricksons need the water to warm up to almost 50 degrees to hatch. Sunshine is almost a requirement for early season Hendrickson hatches. The Hendrickson hatches move up stream as the water warms. At present they are in the upper part of both branches where the release water comes out of the reservoir at about 44 degrees. Without sunshine (like today) the water doesn't get warm enough where the hatch is occuring to allow the bugs to hatch. Caddis (the other early season bug) love sunshine. If it's warm and sunny they hatch in the morning and lay their eggs in the evening, thus extending the hours available for fishing to feeding trout. If it's cloudy, cold and rainy the caddis are no shows at both ends of the day. From my experience it's far better to have warm sunny days in the spring months.
Summer - Now the pendulum swings at least part way. The upper portions of both branches have summer sulfurs that hatch at about 52 degrees. With the thermocline in place, the water coming out of the reservoirs at 44 degrees still needs to be warmed up by sunshine to get optimal sulfur hatches. On the other hand, no one wants to journey down the Big River on a bright sunny July day. The water is too warm for summer bugs to hatch until late evening and often gets too warm to even fish for trout (over 70 degrees). Fish don't really like bright sun. You may have noticed that on a partly cloudy day like Monday, with the water covered with bugs, there were far more fish rising when a cloud covered the sun than when the sun shone brightly. Cloudy rainy days in the summertime allow the water to cool which lets it hold more oxygen which serves to invigorate the trout. They also promote daytime olive hatches (not sure if less light or cooler temps or both are required)
Fall - It gets more complicated. Pseudos, the main fall fly, often hatch in the most miserable cold, rainy and windy weather. But they hatch during the heat of the day ( from 2:00 to 5:00). Not sure what to root for here.
Today - The morning drizzle wiped out both the early caddis hatch and morning spinners. Lack of sun kept the water (where I was) too cold for a good hatch of any kind and the thunderstorms ended the mid afternoon Hendrickson spinners and evening caddis spinners almost before they got started
I have caught my 2 biggest fish ever on bright nearly cloudless to most sunny weather. 2 years ago a fat 18 inch female brown and Monday a 24 inch rainbow, thought it was 26 but when measured against where it’s tail was on the net was closer to 24. Took tour advice and went where the boats were not and had best 2 days of fishing ever in the sunshine on Monday and an hour after the thunder storm in higher dibris laden water. Even risked dunking my phone for a pic of the Bow