I believe that weather is one of the most important factors affecting your fishing days. As we all know, the weather can be unpredictable in this country and can change rapidly. However, it generally correlates with the seasons.
Spring
Spring is often referred to in the classic Mr. Crabtree books as the season of the fly fisher, and there is good reason for this. Most factors that influence a successful day of fishing are favorable during springtime.
As the water temperature rises to a comfortable level, the fish’s metabolism increases, making them more actively search for food. During the spawning process that occurs in winter, trout lose weight and condition, so it becomes crucial for them to eat well to regain their health.
In spring, food becomes more abundant, causing fish to move and rise to the surface, which makes them more visible and accessible to fly anglers. Common flies that can hatch during early spring include Large Dark Olives, Grannom Caddis, Hawthorn Flies, and March Browns. Late Spring, is the time of the Mayfly which is often thought to be the pinnacle of the fly fishing year.
With the ground saturated, water levels on rain-fed rivers are typically high, providing fish plenty of space to move, feed, and find shelter. Additionally, with the sun not too high in the sky, the brightness is often just right, encouraging fish to rise.
Overall, spring is likely the most productive time of year for fly anglers, as fish tend to feed throughout the day.
Summer
Overall, summer is often the most challenging time for fly fishing, which surprises many newcomers to the sport.
By the time summer arrives, fish have feasted on the spring hatches of flies and insects, regaining some of the condition they lost during spawning. While they still want to feed, the conditions can make fish more cautious, resulting in them being fussy about their food or only feeding at specific times of the day.
As we approach summer, river levels in rain-fed streams have dropped considerably due to a lack of rainfall and dry ground. Fish become more cautious about feeding in shallow water and may retreat to deeper runs and pools, making them harder to catch.
During summer, the sun is higher in the sky and shines directly on the river. Bright days are particularly challenging for fishing, as fish are less likely to feed or rise to the surface in strong sunlight. On extremely hot days, especially on slow-moving rivers, water temperatures can exceed 20 degrees Celsius, causing oxygen levels to decrease. This can make fish lethargic and less likely to feed.
There is also often a lull in some fly hatches during the summer, although midges, smuts, and black gnats are still prevalent.
A bright, hot day with low water in the middle of summer is likely to present the worst conditions for fly fishing. Surprisingly, this time of year remains popular among anglers due to the pleasant weather. Under such conditions, fish may stop feeding altogether and hide out of sight during the day, typically only feeding in the early morning, late evening, and often throughout the night.
However, there can be local exceptions. For instance, certain stretches of river, especially those near large dams, may still fish well during the summer due to the consistent temperature and water levels.
There are some positives to summer fishing. If you can choose your days wisely, fishing after a summer storm—when there has been substantial rainfall—can lead to exceptional fishing. This is because, as river levels begin to drop and the water clears, fish often experience a surge in feeding activity.
Autumn
As autumn approaches, the end of the trout season is near, and many anglers tend to hang up their waders. In my opinion, this is a mistake. The last few weeks of the season can offer some phenomenal river fly fishing.
During this time, river levels begin to rise, and the temperature drops, creating favorable fishing conditions. The sun, lower in the sky, means that the days are not as bright. Most importantly, there is a distinct change in the trout. Sensing the shift in season, they prepare for spawning by developing sharper teeth, and the males form a noticeable kype on their lower jaws. This leads to a flurry of feeding activity as they build up their condition in anticipation of the energy-draining spawning process that will occur in the months ahead.
Crucially, the trout become more aggressive as they prepare to defend their territory and secure a mate. With this aggression, they temporarily abandon their usual caution, boldly attacking and chasing after your fly. This behavior can result in some truly memorable fly fishing days.
In fact, some of the best fishing experiences I’ve had have been during the last week of the season, and I always make sure to fit in a few trips before I shift my focus to winter grayling.
Winter
Winter marks the closed season for trout anglers, and care must be taken to avoid areas where trout are spawning. This season is dedicated to grayling fishing. Fortunately, grayling feed even on the coldest winter days. I personally prefer to go grayling fishing when the ground is frosted, as the fish tend to shoal up in various pools in large numbers.
The days are short and dark, with high river levels creating excellent conditions for fishing. Although there are few visual signs of feeding fish on the surface due to the lack of hatches, grayling still feed well. They can be caught using shrimp, caddis larvae, and nymphs near the stream bed. They are not difficult to catch, and a few patterns, such as killer bugs, pheasant tail nymphs, and Czech nymphs, will suffice.
