🐟 Fish Lake Utah Water Temperature Calculator
Estimate surface & depth temperatures, thermocline, and fishing activity at Fish Lake, Utah by season and conditions
| Month | Surface °F | Surface °C | Mid-Depth °F (20–40 ft) | Deep °F (50–70 ft) | Ice / Conditions |
|---|---|---|---|---|---|
| January | 32–34°F | 0–1°C | 33–36°F | 36–39°F | Ice 12–24 in |
| February | 32–35°F | 0–2°C | 33–37°F | 36–40°F | Ice 8–20 in |
| March | 34–42°F | 1–6°C | 34–40°F | 37–41°F | Ice thawing |
| April | 40–50°F | 4–10°C | 38–46°F | 38–43°F | Ice out late Apr |
| May | 48–56°F | 9–13°C | 44–52°F | 40–46°F | Open water |
| June | 54–62°F | 12–17°C | 48–56°F | 42–48°F | Thermocline forms |
| July | 60–67°F | 16–19°C | 52–58°F | 44–50°F | Strong stratification |
| August | 62–68°F | 17–20°C | 54–60°F | 44–50°F | Peak thermocline |
| September | 55–63°F | 13–17°C | 50–58°F | 44–50°F | Turnover begins |
| October | 46–54°F | 8–12°C | 44–52°F | 42–48°F | Fall turnover |
| November | 36–46°F | 2–8°C | 36–44°F | 38–44°F | Pre-ice forming |
| December | 32–37°F | 0–3°C | 33–38°F | 36–41°F | Ice forming |
| Species | Optimal °F | Optimal °C | Active Range | Stress Above | Best Depth (Summer) | Activity Level |
|---|---|---|---|---|---|---|
| Rainbow Trout | 52–58°F | 11–14°C | 44–65°F | 68°F | 10–25 ft | Excellent |
| Splake Trout | 48–55°F | 9–13°C | 38–60°F | 65°F | 15–35 ft | Excellent |
| Mackinaw (Lake Trout) | 48–54°F | 9–12°C | 35–58°F | 65°F | 30–70 ft | Good |
| Yellow Perch | 55–68°F | 13–20°C | 45–75°F | 80°F | 8–25 ft | Good |
| Tiger Trout | 50–58°F | 10–14°C | 40–63°F | 67°F | 12–30 ft | Good |
| Depth (ft) | Depth (m) | Est. Temp °F | Est. Temp °C | Oxygen Level | Best Species |
|---|---|---|---|---|---|
| 0–5 ft | 0–1.5 m | 62–68°F | 17–20°C | Good | Perch (am/pm) |
| 5–15 ft | 1.5–4.6 m | 58–64°F | 14–18°C | Good | Rainbow Trout |
| 15–25 ft | 4.6–7.6 m | 54–60°F | 12–16°C | Excellent | Rainbow, Splake |
| 25–35 ft | 7.6–10.7 m | 48–54°F | 9–12°C | Excellent | Splake, Mackinaw |
| 35–50 ft | 10.7–15.2 m | 43–49°F | 6–9°C | Good | Mackinaw |
| 50–70 ft | 15.2–21.3 m | 39–45°F | 4–7°C | Fair | Mackinaw (deep) |
| 70–100 ft | 21.3–30.5 m | 36–41°F | 2–5°C | Fair | Mackinaw (structure) |
| Temp Range | Species | Presentation | Line Weight | Depth Target |
|---|---|---|---|---|
| 62–68°F | Perch | Jig + worm, small spoons | 4–6 lb mono | 8–20 ft |
| 55–65°F | Rainbow Trout | PowerBait, spinners, flies | 4–8 lb mono | 10–25 ft |
| 50–58°F | Splake | Jigs, spoons, tube baits | 6–10 lb mono | 15–35 ft |
| 48–54°F | Mackinaw | Trolling spoons, swimbaits | 12–17 lb mono | 30–70 ft |
| 32–40°F (Ice) | Perch / Splake | Tungsten jig + minnow | 2–4 lb ice mono | 10–30 ft |
lake water temperature affect more than how folks usually notice. It determines everything, from the behavior of fish to whether they are safe or fun to jump in. There also exists a relation between temperature and dissolved oxygen that at bottom keeps all lives in the water alive.
During the summer the surface of the lake warms up, while the deep parts stay cold. Like this you end up with three separate zones. The upper layer reaches around 65 to 75 degrees and stays warm.
Why Lake Water Temperature Matters
Under it happens a fast drop. The bottom layers however stay cold. Those changes between layers are called thermal layers.
Lakes bigger and deep commonly have very marked differences between those zones. Most lakes overturn their water layers during seasonal change. When the autumn arrives and the air temperatures sink, the surface water cools, sinks down and becomes heavier.
water keeps its temperature much better than air, thanks to its density. So, if it reached 74 degrees during the day, probably it stays close to that even overnight. Sunshine can not reach deep water, so the bottom layer stays cold.
Whether you ever noticed, that water spilled from behind a dam usually has around 50 degrees year-round, regardless of season or outside temperature? Yes, because it comes from the depth. In winter is the surprise: the bottom of the lake commonly is warmer, and hear fish gather.
There exists something called the sweet density spot at 38 degrees, so even if the surface freezes, the water near the bottom commonly hovers around that temperature.
In 2024, one lake reached 68 degrees at only three feet depth almost a week sooner than in prior years. That could mean, that folks can start comfortable swimming sooner than usual. On the other hand, it also stopped the deep blending, that normally spreads oxygen through the whole lake, sooner than normally.
fish search places where they feel good, so the temperature of water gives really useful information for fishing. Cold water makes fish slow and slowly moving. Too warm water makes them sad.
Warm water can not hold a lot of oxygen, that fish need to live. When the oxygen sinks too low, they simply stop activity. Before people thought, that water temperature is the alone main factor affecting the behavior of bass.
Folks believed, that bass are active only when temperatures reach certain levels. If you target certain species, knowing its preferred temperature range really helps. For instance, trout start to feel bad around 70 degrees.
If it passes that, even with close capture and release, you risk to injure them. Species like salmon and trout should not be caught, when the water sharply falls to around 19 degrees Celsius. Want a fast surface reading?
A simple infrared thermometerdoes fine for that.
Data about lake water temperatures come from many sources. Satellites with temperature sensors photograph the Great Lakes and help to create charts of warm flows in the region. Many lakes have installed stations, that permanently monitor.
The Corps of Engineers issues information from its dam monitoring spots, including readings of water temperature.
