Water Temps.

[bassguytom]

I was out yesterday and today. The water around here (outside of Philadelphia) was reading 38 to 41 degrees. All I could manage was a pickerel. My questions is at what temp do the bass start moving to stage for the spawn? Any info. Would be great.

[Paul Roberts]

Bass tend to winter deep but begin to move shallow early -not long after ice out in many waters.

Some studies have shown such movement AT ice out. These initial movements are following the food chain.

 

What they appear to be waiting for in terms of the spawn is temperature stabilization at depth, that is a mass
of water that cannot easily be re-cooled. Once water heats it can hold heat well, thus becomes more stable

temperature-wise. For bass beginning pre-spawn this means a good 10fow hitting and maintaining ~55F.

Fluctuating temps prior can keep them at bay. This 55F number happens to jive with the lethal
temperature for bass eggs. No surprise there I guess. The spawn is normally initiated around 60F.

 

[Dogman65]

Bass tend to winter deep but begin to move shallow early -not long after ice out in many waters.

Some studies have shown such movement AT ice out. These initial movements are following the food chain.

 

What they appear to be waiting for in terms of the spawn is temperature stabilization at depth, that is a mass

of water that cannot easily be re-cooled. Once water heats it can hold heat well, thus becomes more stable

temperature-wise. For bass beginning pre-spawn this means a good 10fow hitting and maintaining ~55F.

Fluctuating temps prior can keep them at bay. This 55F number happens to jive with the lethal

temperature for bass eggs. No surprise there I guess. The spawn is normally initiated around 60F.

 

This may be a dumb question but.....I'm assuming 10fow is 10 feet deep temps your talking about?  If that's the case then is my water temp shown on my depthfinder sorta useless then?  Should I buy some sort of thermometer with a probe on a wire?  I seem to recall seeing them years ago when I was actively fishing.  I'm just starting back up fishing again and I want to actually try to learn something this time.

Also on any particular day do the temps at the surface relate directly to the 10 foot level?  So for example if I'm seeing 41-42 deg.s on my depthfinder (which is an elcheapo model that came on the boat lowrance x4 pro i think) and the I'm seeing 38 at 10 feet will that hold pretty much through the day?  So I just subtract 4 degrees from what I'm seeing on surface temp to know what the weather is at 10 feet?  I'm curious because I was out doing the break in on my boat the other day and the temp raised from 40.2 to 41.4 or so just in the span of a couple hours.  It was sunny and about 48 degrees air temp.  As I moved around the lake the temp varied a degree or two but those temps all raised about 1.2 degrees in that two hours.

 

Thanks,

Dave

[Paul Roberts]

Hi Dave,

 

Yes, that’s temperature at depth.

 

A surface temperature (ST) gauge only scratches the surface. Its relation to deeper temps is not linear –you can’t just subtract a known amount from ST bc surface water heats, and cools, progressively faster than deeper water. And the relationship is not predictable either, because currents and wind come into play.

 

Water temperatures do vary through the day –some days more than others. Angle and availability of direct sunlight, overnight temperatures, and precipitation affect things most. Warm water floats. Cold water sinks. Wind can blow warm water across a cove or pond and stack it on one shore. It can also roll up deeper cold water and change things fast.

When I’m in my boat I keep general track of heating and cooling via the ST gauge on my sonar. I also use a thermometer that I clip onto a sounding rig on a depth coded line, or just clipped to a fishing rod where I have known depth. There are fancier instruments out there but I’ve not owned one. I use this rig to take vertical temperature profiles. These can help me eliminate water directly or simply to get a measured bead on how much heat the water body, or subset of it, is holding. This tells me where in the season I’m at, as this can vary water to water, area to area, on any given date. Just measuring 62F on a good spawning bank doesn’t mean the spawn is on. A temperature profile might tell me that indeed it is early as the depths in that area have not heated enough yet.

I also track temperature changes through the day, esp in different conditions so that I can put measured numbers against conditions and behaviors.

 

One does not NEED such measurements as evidenced by the fact that most anglers don't do it, relying on "reading the signs", and "letting the fish tell you". I still do both these things, but take temps too, as well as keep records. My observations and memories are sloppy enough; I don’t want to be guessing at everything. Measurements help me understand things better. And, if I haven’t been fishing for a while and just drop in cold to a lake, or am at a new lake, knowing waters temps helps give me a starting point much quicker than just guessing.

 

[Goose52]

Wow - Paul - where have you been?  Is it my imagination or have you been MIA for a long time (couple years?).

 

Welcome back...and thanks for the great posts!  

[bassguytom]

Thanks for the info. Still need to warm up a bit for the bite to be on around here.

[Paul Roberts]

Tom, you probably already know this, but, "the bite" starts well before the spawn. The first movments shallow are associated with heavy feeding. Temperature and esp temp changes are an issue at these times though, in terms of fish activity -movements, and willingness to chase and bite.

 

Hey thanks for welcome back, Goose. Yeah I've been MIA -here anyway. My interests run a bit wide. I've been off chasing trout, deer, elk, grouse, and snowhsoe hares. But, I think I'll be after the bass again this year. Sure love it.

 

Oh, and Dave ... One (sometimes two) temp profiles per day (in a pond or specific area of a lake) is sufficient. I fish for fish more than numbers . Surface temps I track all day long, and in multiple areas, as they tell me quite a bit about general heating in the shallows where most bass activity occurs. Each of my journal entries has a small table with time and ST, at least at the start and end of my fishing session. They look like:

 

SE cove:

61F @ 10am

68F@ 3pm

67F@ 6pm

 

Profiles may only have 2 to 4 measurements, depending on depth:

 

SE Cove; Main Channel:

71F ST @ 9am

67F@ 8ft

61F@ 12ft

54F @ 16ft (bottom)

[papajoe222]

I can only speak for us northeners that deal with frozen water during the winter months.

That said, the acutal temp of the water early in the season isn't as important as the direction the water temp. is trending.  By that, I mean a steady increase over a couple of days will get fish moving and feeding. That could only be a few degrees say from 34-38 over three days. A steady decrease will have an adverse effect and will do so in a shorter time period, often within 24hrs. I assume this difference in time vs. fish reactions has to do with water cooling faster than it warms. Because of that, I will often take advantage of a light wind on the second or third day of a warming trend, especiallly if it's blowing into a shallow bay or accross a shallow point.

[Comfortably Numb]

Water here has been 41-44* this winter. we just had three decent weather days around 60* air temp. Main lake today was 46*. Caught some fish today around shoreline in 4-6' on suspending jerkbaits. Last hour of fishing we found 48* in the very ends of the coves in 1-2' water. We killed them there on 1/8 oz jig and craw. Nothing big though and I suspect these fish were relatively shallow all winter.

[Dogman65]

Hi Dave,

 

Yes, that’s temperature at depth.

 

A surface temperature (ST) gauge only scratches the surface. Its relation to deeper temps is not linear –you can’t just subtract a known amount from ST bc surface water heats, and cools, progressively faster than deeper water. And the relationship is not predictable either, because currents and wind come into play.

 

Water temperatures do vary through the day –some days more than others. Angle and availability of direct sunlight, overnight temperatures, and precipitation affect things most. Warm water floats. Cold water sinks. Wind can blow warm water across a cove or pond and stack it on one shore. It can also roll up deeper cold water and change things fast.

When I’m in my boat I keep general track of heating and cooling via the ST gauge on my sonar. I also use a thermometer that I clip onto a sounding rig on a depth coded line, or just clipped to a fishing rod where I have known depth. There are fancier instruments out there but I’ve not owned one. I use this rig to take vertical temperature profiles. These can help me eliminate water directly or simply to get a measured bead on how much heat the water body, or subset of it, is holding. This tells me where in the season I’m at, as this can vary water to water, area to area, on any given date. Just measuring 62F on a good spawning bank doesn’t mean the spawn is on. A temperature profile might tell me that indeed it is early as the depths in that area have not heated enough yet.

I also track temperature changes through the day, esp in different conditions so that I can put measured numbers against conditions and behaviors.

 

One does not NEED such measurements as evidenced by the fact that most anglers don't do it, relying on "reading the signs", and "letting the fish tell you". I still do both these things, but take temps too, as well as keep records. My observations and memories are sloppy enough; I don’t want to be guessing at everything. Measurements help me understand things better. And, if I haven’t been fishing for a while and just drop in cold to a lake, or am at a new lake, knowing waters temps helps give me a starting point much quicker than just guessing.

 

Thanks Paul,

This makes me want to get a thermometer with a probe.  I'm just starting out (restarting) and need all the help I can get.  This is good info.

Dave

[Deleted account]

I can only speak for us northeners that deal with frozen water during the winter months.

That said, the acutal temp of the water early in the season isn't as important as the direction the water temp. is trending.  By that, I mean a steady increase over a couple of days will get fish moving and feeding. That could only be a few degrees say from 34-38 over three days. A steady decrease will have an adverse effect and will do so in a shorter time period, often within 24hrs. I assume this difference in time vs. fish reactions has to do with water cooling faster than it warms. Because of that, I will often take advantage of a light wind on the second or third day of a warming trend, especiallly if it's blowing into a shallow bay or accross a shallow point.

 

 

This ^.

[Comfortably Numb]

Water here has been 41-44* this winter. we just had three decent weather days around 60* air temp. Main lake today was 46*. Caught some fish today around shoreline in 4-6' on suspending jerkbaits. Last hour of fishing we found 48* in the very ends of the coves in 1-2' water. We killed them there on 1/8 oz jig and craw. Nothing big though and I suspect these fish were relatively shallow all winter.

 

Water here has been 41-44* this winter. we just had three decent weather days around 60* air temp. Main lake today was 46*. Caught some fish today around shoreline in 4-6' on suspending jerkbaits. Last hour of fishing we found 48* in the very ends of the coves in 1-2' water. We killed them there on 1/8 oz jig and craw. Nothing big though and I suspect these fish were relatively shallow all winter.

 

Wow. Did not get to cold last night and today was sunny and 65*. Water temp was 49-50* and 55* in the shallows. Fish really turned on and the shallow light jig and Senko bite was great. Seemed to go from winter to pre-spawn behavior over night

[WRB]

Water temperature at the surface where you measure it is not the water temperature where the bass are located...bass don't live on the surface!

Pre spawn everywhere following the winter cold water period is 55 to 60 degrees +/-2 ....at the depth bass are holding in. Holding is the depth they suspend at while resting. The spawn generally starts when the weather stabilizes and the protected areas is about 62 to 65 degrees between 2' to 8'. Smallmouth and spotted bass about 2 degrees colder.

There are several waves of spawner's and some females spawn several times within a few weeks time. The late spawn normally ends at 67 degrees due to infestation of bluegill and sunfish raiding the nest sites.

Tom