Best Water Temperature for Flounder Fishing (Complete Guide)

Flounder are one of the best-eating and targeted ocean fish in both inshore and nearshore waters but understanding the best water temperatures and ranges will better improve your catch odds. Is there a preferred temperature range for flounder?

The best water temperature for catching all species of flounder is generally between 55-68º F, although there are some noted differences in water temperature preferences between flounder of Atlantic, Pacific, and southern waters of the United States.

Like all species of fish, flounder change their location and feeding pattern based on their ambient conditions, the most important of which is the ambient temperature of their body of water.  Knowing how they behave in response to temperature changes can greatly improve your chances of landing a big one with the appropriate response in your angling style.

This article will cover how temperature affects flounder movement and feeding patterns, what kind of food sources they prefer at different temperatures, and things to look out for with weather and temperature patterns to improve your fishing experience.

Best Water Temperature for Flounder

While there are 5 different main species of flounder in the U.S., there is a particular pattern most flounder will follow when considering temperature changes, with their main difference being found in their spawning period. On the East coast, you have typically three species of flounder occupying the Gulf Coasts and the Atlantic, which are southern flounder, summer flounder, and winter flounder.

On the West Coast, you can typically find California flounder and starry flounder. One common theme among most flatfish is their metabolic response to temperature. Flounder tend to be found near shore year-round but will slow down significantly and seek the steadier temperatures of the depths in the colder seasons on both sides of the country, making it generally easy to shift your fishing strategy for all species based on similar principles. 

With the colder habitats on the Atlantic side, when the surface temperature dives below 58º Fahrenheit and begins to remain consistently cooler, flounder will begin to seek deeper water and find shelter near large rock piles and debris on the ocean floor.

As surface water temperatures rise above that 60º mark again and become more steady in the late spring and summer, flounder will be found in numbers seeking food close to the shore. This makes anything between the 55-62º temperature range arguably the best time for the Atlantic species, when they’re at their hungriest and most ready to seek bait. 

The North Pacific has similar effects on flounder feeding habits to the Atlantic, while the Southern Pacific is more generous throughout the year with flounders favoring the shore most of the time. On the southern side, when surface temperatures hit above 70º, the flounder will typically move further out for protection against the heat. This makes anything between the 58-68º perfect for flounder on the Pacific side. 

Flounder Depth & Habitat by Temperature

As stated above, flounders have fairly straightforward movement patterns depending on ambient water temperature. Flounder can be found seeking crustaceans and small baitfish as near as 20-50 yards from the shore, making them one of the easiest fish to find in warmer seasons.

They tend to prefer the surface when surface temperatures are warmer than 58º and can be found at depths between 5 and 30 feet, with their position in the water column only varying based on their distance from the shore. 

However, in the colder seasons (especially on the Atlantic and in the Gulf of Mexico), flounder will favor more significant depths 30-40 miles from shore, where they’ll typically be found at the bottom near rocky crops, sunk ships, and other kinds of covering habitat. This is especially the case during their spawning period between November and January, with their peak spawn typically being in December in the Gulf and Atlantic. 

For a complete breakdown of the best times & seasons for San Diego fishing, please check out this helpful article.

Seasonal Considerations and Water Temperature

Winter

Winter and early spring is one of the most particular seasons for catching flounder on both sides of the country, with movement patterns being more frequent and centered around their spawning periods and cover-seeking tendencies.

Depending on the species, flounder spawning happens as early as November and as late as February, where flounder can be found at depths between 60 and 200ft of water. At this time of year, shore fishing is typically at its worst with flounder mostly being found 30 or more miles from shore where they hug the bottom. 

Low water temperature slows down their feeding habits where they’ll typically focus on finding crustaceans and very small baitfish at the lower water column. Their spawning period is accompanied by a temporary anorexic phase where they will mostly respond to a very slow approach to angling the bottom.

Immediately following their spawning period they will begin to pick up in activity, even far from the shore while shore surface temperatures remain below in the high 40s and lower 50º ranges.

Spring

In the early Spring, winter flounder may still be found in the middle of their spawning phase out from the Gulf and the Atlantic. Most species of flounder will continue to favor greater depths and distance from the shore, and feeding patterns should resemble winter feeding until water temperatures begin to rise to a steady temperature in the low 60s.

Late spring is a time when most flounder will begin to be at their most active close to shore, and will be in a post-spawn feeding frenzy where they’ll respond well to high-speed trolling 30-40 yards from the shore. Shore fishing is also prime at this time from late spring up into the summer months.

Summer

Summer is arguably the most consistent time of year on both sides of the coast for catching all species of flounder. Favoring the shore and depths between 5 and 20 feet of water, flounder will respond very well to bait and will be ready to snap at anything nearby.

On particularly hot days where surface temperature rises to above 70º, flounder may seek floor vegetation or dock cover near the coast, or move temporarily to further depths to seek shelter from the sun. Feeding patterns remain very steady throughout the summer and up into the early fall.

Fall

Early fall is a continuation of the prime summer fishing, with flounder responding very well to bait and continuing to remain close to shore. However, with sudden temperature drops flounder will begin to migrate much farther from shore where they’ll be found at winter depths (50-200ft) and as far as 40 miles out.

Winter flounder tend to be closer to shore the longest on the Atlantic side before transitioning out to their spawning waters. 

Does Water Temperature Affect Flounder Feeding? 

Flatfish have a particular metabolic response to temperature making them much more keen to feed in hotter weather than when surface temperatures begin to fall. At temperatures above 60º, flounder will seek small invertebrates, shrimp, clams, smaller baitfish like menhaden, anchovies, pinfish, and mullet, and certain species will even feed on plankton.

This makes bloodworms, sandworms, and cut clam or anchovies particularly good bait in the warmer season. At warmer temperatures, flounder will feed both in and out of cover depending on outside conditions.    

One of the things that makes winter fishing particularly difficult for flounder is the length of their spawning period. Having a much wider range for when spawning occurs than many other species, flounder will potentially be spawning throughout the entirety winter and even into the early spring, where they will be anorexic and much less likely to feed.

Flounder will still respond opportunistically to baitfish and small invertebrates at this time, making cut bait and imitation lures particularly effective at these times. 

To learn the best time of day to catch flounder, please check out this helpful article I wrote. Also, if flounder fishing in Florida, learn when the best times and seasons to catch fish in Florida is with this other helpful guide I wrote.

To see my complete breakdown of the best water temperatures for fishing (all species both freshwater and saltwater), please check out this helpful article. If you ever want to fish Charleston, this helpful article I wrote on the best times to fish Charleston will really help you out.

Impacts of Weather Changes and Breaks on Flounder

Flounder are incredibly responsive to weather changes and breaks in weather patterns which makes it important to understand their reactions to the weather to improve your angling. Flounder are saltwater species with surface-feeding tendencies.

Heavy rain can bring in more freshwater making the surface water temporarily more brackish, driving flounder toward deeper waters where they’ll be less focused on feeding. This has the same effect as freshwater runoff into the ocean, which makes flounder avoid these areas for more consistent and clearer saltwater shores. 

Days with light rain can reportedly improve your chances of catching flounder, as it forms temporarily cooler and more turbid waters in the late spring and early summer. Snow has no particular impact on flounder feeding habits given their relative depth during the winter months. 

Breaks in rain leading to days and even weeks in consistent sunny weather are a huge boon to flounder feeding, particularly in the north Pacific and Atlantic/Gulf regions. Especially with waters in the mid to high 50s and low 60s, flounder will be particularly keen on most of their preferred bait in these kinds of weather. 

Water Temperatures & Spawning

Flounder will typically begin their spawning period as soon as water temperatures move into optimal ranges in the winter season. While winter flounder tend to favor spawning immediately prior to upward shifts to warmer temperature (favoring late winter and early spring), most species of flounder will ideally spawn when water temperatures are between 32 and 50 degrees Fahrenheit between the months of November and January.

Optimal water temperatures for flounder are consistent between these temperatures due to higher chances of their eggs surviving and not being at risk to predators. When there is more variable weather and consistent turbidity at lower depths in the early winter, flounder will typically avoid spawning until later months, though there are outlier females who will begin spawning before improved temperatures.

Flounder seek cover and consistency 30-40 miles from shore at these times, where they may be found from 50 to 200 ft of depth depending on surface conditions.

3 Tips for Catching Flounder According to Water Temperature 

1. Flounder favor consistent sunlight 

Whether you’re fishing from the shore or deep out in the winter, flounder will typically prefer clearer waters with more sunlight. This is especially the case in the North Pacific and Gulf/Atlantic areas but holds true for California as well except for on the hottest days. Flounder prefer high visibility and waters with consistent surface temperatures between the mid-50s and 60s. 

2. Avoid brackish waters and heavy rain

Flounder avoid brackish areas with nearby freshwater runoff. They are strictly saltwater fish and also avoid heavily turbid areas due to their reliance on sight and their tendency to hug the bottom in search of food. Rain will also bring in freshwater from the surface, which drives flounder toward more favorable waters deeper out, and temporarily disrupts their feeding pattern. Clear, calm days with consistent temperature and saltwater conditions are best.

3. Select the appropriate bait and approach for the time of year

Flounder will heavily shift their focus on bait throughout the year, especially with the changing of water temperature. While bloodworms and other kinds of shore favoring bait are good in the summer, they will be less effective than cut clam or baitfish like anchovies in the winter.

Flounder eat a wide variety of bait throughout the year, however, and are known to be particularly opportunistic immediately following their spawning period. 

Flounder will also respond much better to a slower angling approach in the winter than in the summer. Flounder pounce on anything that touches the bottom, but may avoid anything at higher depths or which moves too fast. This is the opposite of the summer, where flounder will tend to hug the bottom and opportunistically move up as they see baitfish or shrimp.

For a complete breakdown of the best times to fish Mobile, Alabama, please check out this helpful article I wrote. For a complete breakdown of the best water temperature for surf fishing, check out this article. For a complete breakdown of the best water temperature for tarpon fishing, check out this article.