Not everyone has the luxury of time to go fishing as often as they want. Maybe you only have the weekends, or a day here and there, to devote to fly fishing.
It can be especially frustrating when the clouds loom overhead and the rain starts as you make the first cast. However, if you are only looking for nice weather to go fishing, you may be missing out.
So, can you fly fish in the rain? Absolutely. Some of the best fly fishing action occurs in the rain. Intense feeding frenzies start when insects and other food sources for feeding trout are washed into the stream by rain. You can also expect to catch plenty of fish before and after a heavy rain.
Not all rain is created equal though. It is important to understand when rain might trigger trout to feed or when it shuts them off instead. Keep reading and you will see what I mean.
Common rain conditions
When it looks like fly fishing in the rain is imminent, being able to adapt your techniques to match the current rain conditions is key.
Heavy rain does not always mean you should put away the dry fly. If you can see that trout are still actively rising, keep fishing the dry fly during the beginning of a downpour.
Flying insects are usually forced onto the surface in the first minutes of heavy rain and the trout will take advantage of this. As long as you can differentiate a strike amid the chaos of rain drops, you’re good to go.
An hour or more of heavy rain eventually causes a rise in water level and slightly muddier water as well. At this point, trout may stop rising and it is time to switch to a nymph rig. The heavy rain and increased volume in the stream stirs up more food bellow the surface than on top. Try brighter colors when the color of the water decreases the visibility of the fly.
High water conditions are prime times to use worm imitators. Worms come out during rains and offering a tasty piece of protein often works when nothing else does. The San Juan worm in pink or red is a popular choice. It has made the difference for me on numerous occasions during a deluge of heavy rain.
It is tricky to predict the affects of heavy or moderate rain that is significantly lower in temperature than normal. Cold rains arrive during cold fronts or intense thunder storms.
I have mixed experience with this type of rain and it depends greatly on the time of year and the temperature of the previous few days.
Cold rain that interrupts hot, dry, summer days can really boost insect hatches and initiate heavy surface feeding shortly after. A warm, sunny day following a cold rain also causes dew in the early morning hours that are stellar for dry fly presentations like small midge or gnat patterns.
Just a quick word of caution. Fishing during thunder and lightning storms is dangerous. Waving a 9 foot lightning rod around is a bad idea. Head for cover and come back when the storm passes.
Light rain or drizzle
Steady conditions that produce light rain are not associated with changes in feeding patterns or the behaviors of trout. I apply the same tactics as I would during fair weather conditions. The biggest challenge you may face during a constant drizzle is just staying comfortable.
Timing of the rain
Deciding if you should only fish before, during or after a rain storm depends on barometric changes. Air pressure has been shown to affect fish behavior. Personally, I just fish when I can. For those of you who prefer a more scientific approach, let’s discuss pressure changes.
Falling barometer and low pressure
A falling barometer indicates an approaching weather front that may bring rain. Fish are likely to increase their activity and prepare for cold fronts by ramping up on the search for food.
Once the low pressure arrives and the rain starts, trout feed as I described above. Sustained low pressure and low temperatures can turn off the bite. Or so it may seem. Always switch fly patterns once or twice before packing up and calling it a day.
Sometimes prolonged rain forces fish to find cover. They still feed but you need to present the fly as close as possible to where they might be holding.
Rising barometer and high pressure
When the storm passes and the rain has stopped, trout resume normal feeding patterns. Fish may be on the move as they leave tighter cover to return to normal holding spots to feed again.
Remember, if the rain storm is followed by warming temperatures, a mega hatch could be in the cards. You do not want to miss it!
Rainy day fly collection
When you have enough awesome days fly fishing in the rain, you will start to put a collection of flies together. At least I did. My rainy weather flies give me the ability to change patterns that follow the progress of the rain. It seldom fails me and I usually have at least one fly that strikes gold.
A standard selection of dry flies is sufficient for most rainy days. Adams, elk hair caddis, midges and gnats are all effective. Heavy rains make it hard to see subtle strikes, so I like to use slightly larger patterns for visibility. Size 12 is a good size to try first.
Midges and gnat patterns are often tied on tiny hooks. They are hard to see during heavy rains but don’t skip them if larger dries are not working and the fish are rising.
The last insects to be beaten down onto the surface during a hard rain are the tiny ones. Even if you can’t see the fly, experienced fly anglers can recognize a strike by small but sudden movement of the fly line.
Having a hard time keeping your dry fly from sinking? Check out my article that will teach you how to solve that problem.
All the beetles, hoppers, ants and worms that cling to the grass and soil alongside streams get washed into the fray by the rain. Keep a few on hand when sudden late spring or summer rains blow through.
When the trout lose interest in the surface bugs, make the switch to nymphs. You may need to get their attention as the water gets some color in it. Shiny bead-head patterns are my first pick. Soft hackle flies tied with yellow or orange bodies are hard for sub-surface feeders to resist as well.
Try running a double nymph rig with a couple different patterns to help find what they like. What worked before the rain may not interest them after 30 minutes of downpour. Experiment until you find the recipe for success.
When the nymphs fail to produce during the rain, move on to streamers. Dark colors that contrast well in turbid water are my first choice. Black or olive bead-head wooly buggers and muddler minnows always have a spot in my fly box.
The next time you have the urge to cast a fly into your favorite trout stream, don’t be afraid of the rain. Gear up with a good rain jacket and come prepared for some of the finest fishing of the season. You won’t want to miss a single “drop” of action!