Best Water Temperatures for Brown Trout Fishing (Guide)

Water temperature is the most crucial thing to consider when setting off to fish for brown trout, and it can decide how you should approach your angling to net the most fish.

For brown trout fishing, water temperatures between 50 to 60 degrees Fahrenheit (10 to 15.5 degrees Celsius) are ideal, with the best fishing conditions usually found when the water temperature is around 55 to 57 degrees Fahrenheit (12.5 to 14 degrees Celsius).

Water Temperature (°F)	Quality of Brown Trout Fishing
Below 40°	Less active, slow movements, may be lethargic.
41-50°	Becoming more active, moving to shallower areas.
51-60°	Active, feeding more, actively searching for food.
61-68°	Very active, actively feeding, often near structures.
69-73°	Active and feeding, actively chasing prey.
Above 74°	Becoming less active, seeking cooler areas.

While even seasoned fishermen might tell you that brown trout will bite at any temperature (which isn’t entirely wrong), there are certain things to consider in how differences in temperature and sudden shifts can change brown trout feeding habits.

This article will cover the ideal temperatures for brown trout fishing, emphasizing typical behavior at given temperature ranges, what baits and lures to use for different conditions, and how brown trout react to storms and sudden changes in water temperature.

Brown Trout Fishing by Water Temperature

Below 40°

Brown trout become less active and feed less frequently when the water temperature is below 40 degrees Fahrenheit (4.4 degrees Celsius). Here’s what you need to know:

Brown trout tend to move to deeper, slower-moving areas like deep pools or slower sections of the river to conserve energy.
They focus on small aquatic insects and other small organisms present year-round in the water.
Since their activity levels are lower, using slow and subtle techniques is best. Nymph flies imitating small insects like midges and stoneflies are effective.

41-50°

Brown trout are still active and looking for food when the water temperature is between 41 and 50 degrees Fahrenheit (5 to 10 degrees Celsius). Here’s what you need to know:

In cooler water around 41-45 degrees Fahrenheit, brown trout often stay in deeper areas like pools and slower currents. They focus on insects like stoneflies and midges. Using nymph flies that imitate these insects underwater can be effective.
As the water warms towards 46-50 degrees Fahrenheit, brown trout might move to slightly shallower areas and feed more actively. They could still be eating nymphs and larger insects. Presenting your flies using techniques like dead-drifting or slow retrieves can work well.

51-60°

Brown trout are usually active and eager to eat when the water temperature is between 51 and 60 degrees Fahrenheit (10.5 to 15.5 degrees Celsius). They can be found in different parts of the river:

In cooler water around 51-55 degrees Fahrenheit, brown trout may be in faster areas like riffles and runs, searching for insects like mayflies and caddisflies. Dry flies resembling these insects on the water’s surface can be effective.
As the water warms towards 56-60 degrees Fahrenheit, brown trout might move to deeper pools and shady spots to stay comfortable. They could focus on larger insects and small fish. Using nymph flies that look like these food sources underwater can work well.

61-68°

Brown trout are usually active and continue feeding in water temperatures ranging from 61 to 68 degrees Fahrenheit (16 to 20 degrees Celsius). They can be found in different parts of the river, depending on the specific temperature:

In cooler water closer to 61-65 degrees Fahrenheit, brown trout might stay in faster-moving areas like riffles and runs, looking for insects like mayflies and caddisflies. Dry flies that imitate these insects on the water’s surface can be effective.
As the water warms towards 66-68 degrees Fahrenheit, brown trout might move to deeper pools and shaded spots to stay comfortable. They could focus on larger insects and small fish. Using nymph flies that mimic these food sources underwater can work well.

69-73°

In water temperatures below 69-73 degrees Fahrenheit (20.5-22.8 degrees Celsius), brown trout remain active and continue to feed, although their behavior can change based on the specific temperature:

In cooler temperatures closer to 69 degrees Fahrenheit, brown trout might stay in faster-moving areas like riffles and runs, where the water is well-oxygenated. They feed on insects like mayflies and caddisflies. Dry flies that imitate these insects on the water’s surface can be effective.
As the water warms towards 73 degrees Fahrenheit, brown trout might seek out deeper pockets and shaded spots to stay comfortable. They can still be found in runs and pools, focusing on aquatic insects and small fish. Nymph flies that resemble these food sources can work well, presented near the riverbed.

Above 74°

Brown trout become more cautious and selective about feeding when the water temperature goes above 74 degrees Fahrenheit (23.3 degrees Celsius). Here’s what you need to know:

Brown trout might move to cooler, shaded areas like under overhanging trees or deeper pools to escape the warmer water.
They could focus on finding active insects on the surface, like grasshoppers or other terrestrial bugs.
Brown trout tend to feed more actively during the cooler parts of the day, like early morning or late afternoon.

Using dry flies that imitate the insects they’re focused on can work well in these conditions. Making delicate casts and presenting your fly softly on the water’s surface can entice them to strike.

Brown Trout Fly Fishing: Best Water Temps

Best Water Temperature: Nymphs

The best water temperature range for nymph fishing can vary depending on the season. In general, for nymph fishing:

Spring: Look for water temperatures around 50 to 60 degrees Fahrenheit.
Summer: Target temperatures between 55 to 65 degrees Fahrenheit.
Fall: Aim for temperatures ranging from 45 to 55 degrees Fahrenheit.
Winter: Seek out temperatures around 40 to 45 degrees Fahrenheit.

Best Water Temperature: Streamers

For streamer fishing to catch brown trout, the best water temperature range can vary with the seasons:

Spring: Aim for water temperatures around 45 to 55 degrees Fahrenheit.
Summer: Look for temperatures between 55 to 65 degrees Fahrenheit.
Fall: Target temperatures ranging from 50 to 60 degrees Fahrenheit.
Winter: Seek out temperatures around 40 to 50 degrees Fahrenheit.

Best Water Temperature: Dry Flies

For dry fly fishing to catch brown trout, the best water temperature range can vary with the seasons:

Spring: Aim for water temperatures around 50 to 60 degrees Fahrenheit.
Summer: Look for temperatures between 60 to 70 degrees Fahrenheit.
Fall: Target temperatures ranging from 55 to 65 degrees Fahrenheit.
Winter: Seek out temperatures around 45 to 55 degrees Fahrenheit.

Best Water Temperature: Mice Flies

For fishing with mice flies to catch brown trout, the best water temperature range can vary depending on the seasons:

Spring: Look for water temperatures around 45 to 55 degrees Fahrenheit.
Summer: Aim for temperatures between 55 to 65 degrees Fahrenheit.
Fall: Target temperatures ranging from 50 to 60 degrees Fahrenheit.
Winter: Seek out temperatures around 40 to 50 degrees Fahrenheit.

Is Water Temperature a Big Factor in Brown Trout Fishing?

Water temperature has a big impact on brown trout fishing and their behavior. Brown trout tend to be less active when the water is cold, like in winter or early spring. They might stay in deeper parts of the water where it’s warmer and feed less frequently.

Brown trout become more active as the water warms up in late spring and summer. They move to shallower areas, like riffles or runs, to find cooler and oxygen-rich water. Warmer water speeds up their metabolism, so they must eat more often.

In fall, brown trout become more active and aggressive in feeding as water temperatures cool down again. However, extremely cold water, like during winter, can make them less willing to bite.

Overall, the right water temperature can make brown trout more energetic and more likely to bite, while cold or warm water can slow down their activity.

Seasonal Water Temperature Guide for Brown Trout

Winter

In early winter, when water temperatures drop to around 40 to 45 degrees Fahrenheit (4.4 to 7.2 degrees Celsius), brown trout become less active and might move to deeper, slower-moving parts of rivers and streams. They focus on conserving energy rather than actively feeding. Fishing during the warmer parts of the day when the water temperature slightly rises can increase the chances of success. Using nymph flies that imitate aquatic insects close to the riverbed can work well during this time.

In the middle of winter, brown trout’s metabolism slows down even more when water temperatures further drop to around 35 to 40 degrees Fahrenheit (1.7 to 4.4 degrees Celsius). They prefer deeper, quieter waters to minimize energy expenditure. Fishing very slowly with tiny nymphs or midge larvae imitations, presented right before them, can entice a bite.

In late winter, brown trout are the least active when water temperatures are at their coldest, around 32 to 37 degrees Fahrenheit (0 to 2.8 degrees Celsius). They often hold in the deepest pools where water temperatures are more stable. Fishing extremely patiently with small, dark-colored flies that resemble insects in their dormant state, such as midges or small stoneflies, can be effective.

Overall, in winter, fishing for brown trout can be tough due to their reduced activity. Warmer parts of the day and slow presentations with small, natural-looking flies are key strategies.

Spring

In early spring, brown trout wake up from their winter slowdown when water temperatures range from 40 to 50 degrees Fahrenheit (4.4 to 10 degrees Celsius). They become more active, moving from deeper areas to shallower spots like riffles and runs, where the water is more oxygen-rich. They focus on easy-to-catch food like insects and small fish. Using nymph flies that imitate underwater insects, and fishing them close to the riverbed, can work well during this time.

In the middle of spring, brown trout become even more active as water temperatures rise to around 50 to 55 degrees Fahrenheit (10 to 12.8 degrees Celsius). They feed on emerging insects and might be found near the surface. Dry flies that resemble insects on the water’s surface can be effective, especially during hatches.

In late spring, brown trout are more active and more willing to chase their prey when water temperatures reach 55 to 60 degrees Fahrenheit (12.8 to 15.5 degrees Celsius). They can be found in various parts of the river, including pockets behind rocks or near fallen trees. Streamer flies that mimic small fish or large insects can be successful, as brown trout become more aggressive.

Brown trout fishing is good in spring when water temperatures are between 40 to 60 degrees Fahrenheit (4.4 to 15.5 degrees Celsius).

Summer

In early summer, when water temperatures rise to around 55 to 60 degrees Fahrenheit (12.8 to 15.5 degrees Celsius), brown trout become more active and move into faster currents like riffles and runs. They’re hungry after the spawn and focus on insects like mayflies and caddisflies. Dry flies that imitate these insects on the water’s surface can be successful during hatches.

In the middle of summer, brown trout feed actively as water temperatures increase to around 60 to 65 degrees Fahrenheit (15.5 to 18.3 degrees Celsius). They may move to deeper pockets with more shade to stay cooler during the day’s heat. Nymph flies that mimic aquatic insects underwater can be effective, especially in the early morning or late evening.

In late summer, when water temperatures peak around 65 to 70 degrees Fahrenheit (18.3 to 21.1 degrees Celsius), brown trout’s activity might slow down a bit due to warmer conditions. They may seek cooler, oxygen-rich areas like spring-fed creeks or shaded spots. Using streamer flies that mimic small fish and fishing during the cooler parts of the day can improve success.

Brown trout fishing can be good in summer when water temperatures range from 55 to 65 degrees Fahrenheit (12.8 to 18.3 degrees Celsius).

Fall

In early fall, brown trout become more active after the warm summer when water temperatures range from 50 to 55 degrees Fahrenheit (10 to 12.8 degrees Celsius). They move into shallower water and might be found near rocks, fallen leaves, or other structures. Brown trout start to feed more aggressively, focusing on insects and small fish. Using streamer flies that mimic small fish can be effective during this time.

In the middle of fall, brown trout continue their feeding spree as water temperatures drop to around 45 to 50 degrees Fahrenheit (7.2 to 10 degrees Celsius). They can be found in deeper pools or runs and might be more willing to chase larger prey. Using nymph or streamer flies resembling insects and small fish can work well, as brown trout become more aggressive.

In late fall, when water temperatures further decrease to around 40 to 45 degrees Fahrenheit (4.4 to 7.2 degrees Celsius), brown trout prepare for the upcoming winter. They focus on fattening up and might move to deeper, slower water. Nymph flies that imitate aquatic insects or smaller streamer patterns can still be effective, presented close to the riverbed.

Overall, in fall, brown trout fishing can be very good when water temperatures range from 45 to 55 degrees Fahrenheit (7.2 to 12.8 degrees Celsius). Brown trout are actively feeding, and using a mix of streamers and nymph flies can increase your chances of catching them.

Does Air Temperature Impact Brown Trout Fishing?

Air temperature affects brown trout fishing because it can influence the water temperature, affecting how brown trout behave. When the air is cold, like in winter or during chilly days, it cools down the water. Cooler water temperatures can make brown trout less active and move slower. They might become sluggish and less likely to bite.

Conversely, when the air is warm, like during spring and summer, it gradually warms up the water. Warmer water temperatures can make brown trout more active and willing to move around and feed. They become more energetic and might venture to shallower areas to find food.

In summary, air temperature is key in determining water temperature, directly impacting brown trout activity and feeding behavior.

How Cold is Too Cold for Brown Trout Fishing?

Brown trout fishing is usually less productive when the water temperature is very cold, below 40 degrees Fahrenheit (4.4 degrees Celsius). Brown trout might become slower and less active at this point, making them less likely to bite. If the air is also frigid, like during freezing winter days, it can further cool down the water, making the fishing conditions even more challenging.

In general, when both the air and water temperatures are extremely cold, it can indicate that brown trout are less likely to feed actively, and fishing might be tougher.

How Hot is Too Hot for Brown Trout Fishing?

For brown trout fishing, water temperatures that are too cold, below 40 degrees Fahrenheit (4.4 degrees Celsius), or too warm, above 70 degrees Fahrenheit (21.1 degrees Celsius), can make fishing less productive. When it’s too cold, brown trout become less active and might not bite readily. Brown trout can become stressed when it’s too warm because they prefer cooler water.

Similarly, if the air is too cold, like during frosty mornings or chilly days, it can impact the water temperature and slow down brown trout activity. If the air is too hot, like during scorching heatwaves, it can warm up the water and make brown trout less likely to bite.

In summary, brown trout fishing is usually best when the water temperature ranges from 50 to 60 degrees Fahrenheit (10 to 15.5 degrees Celsius) and when the air temperature is moderate and comfortable.

Storms & Weather Changes: Impact on Brown Trout Fishing

Storms and weather can affect brown trout fishing in different ways. Brown trout can become more active and feed more actively before a storm, like a rainstorm or a change in atmospheric pressure. This can create good fishing opportunities.

During a storm, however, fishing can become more challenging and even dangerous due to heavy rain, strong winds, and lightning. Brown trout might become less active and stop feeding during the storm’s disturbance.

After a storm passes, the fishing can pick up again. Brown trout may continue feeding as water conditions stabilize. Rain can also wash insects and other food into the water, making brown trout more likely to bite.

In general, calm and mild weather is better for brown trout fishing, but sometimes the moments before and after a storm can offer great chances to catch them.

Click here to see the best water temperature for trout. Click here to see how to catch trout on cloudy days. Click here to see how to catch trout on sunny days. Click here to see how to catch trout on windy days. Click here to see the best water temperature for rainbow trout.