What are your surface temps as of 4/27/13? My biggest pond today is 57 F. on the surface. 51 F. near the bottom. I don't have the diffusers set up yet as I just refilled it. How about yours?

50 F at 6" and 47 F at 12 feet

So you must be really warming up there compared to the last few weeks?

70 F on the surface, 62 F on the bottom.

what do you guys use for surface and bottom temps? I need to get something new (a muskrat stole my last thermometer!).

According to my laser gun 58 degrees surface. Cold rain last night.

I'm using a YSI 550A D.O. meter that also has a temp sensor.

I haven't taken temps at my pond but I can tell you that it has finally warmed up enough for bullfrogs to reappear yesterday. That was the first time I seen them in the last 10-12 days, the last cold front that came through really knocked our water temps down here.

Back on 4/20/13 I fished one of our public lakes, when we launched the boat at 7:00 AM the surface temp was just 39 degrees and we spent the first 2 hours cleaning ice out of the guides on every other cast until air temps got above freezing. When we pulled off the water at 2:00 PM the surface temps had warmed to 44 degrees.

Fast forward a week and the high today here is supposed to hit 80 degrees. My best guess is that water temps are in the mid to upper 50's now.

If you can find something with a Platinum RTD (Resistance Temperature Detector), that will be your most accurate.

The YSI meters that both Dwight and Cecil have utilize Pt RTD's. If they tell me the temperature they measured, I believe them. RTD's are slow to respond so you need to let them settle out. Typically within 10 seconds. Quite accurate tho, and are very stable.

Another thing I like to use are Thermocouples. There are many types for different applications. The most typical I use are Type "J". If what you are measuring can be within a few degrees, then you can use them out of the box. You can also get these NIST Certified which will tell you the offset. One I have here that has a -2.2F offset, so if it's reading 60F, it's actually 57.8F. You can also go the one time calibration rout.

Consumer grade goods like these are sooooooo frustrating to me. I can see the outside and read the description, but I can't see the inside, and they never tell you what the heck it really is!

I don't think you have to be super precise about pond temp. measurement, unless you are working on a scientific angle.

Hope that wasn't confusing.

Good points Phil. And you do get what you pay for. I bought two digital temp gauges really cheap off of Amazon. Both gave different readings for the same tank and neither lasted more than few weeks. Absolute Chinese made junk.

My cheap floating aquarium thermometer showed 58 degrees at 10:00 AM this morning.

I'll be willing to bet that you really do not know what the actual temperature is. Good enough tho!

Yeah, I get a really bad headache looking at some of that stuff.

It's close enough, I have two of them and they vary just one degree apart. I would bet that it is not off more than 2-3 degrees.

Quite possibly, but you just never really know

Medical grade, like the glass ones with the red (or other color) stuff inside, where the Doc shoves it into a body orifice. Those are quite accurate, and probably not too expensive either.

You sure about that Phil? From my limited experience in the medical field every is expensive!

My cheap aquarium thermometer is now reading 65 degrees on the shallow north side of my pond. It was showing 84 degrees for the air temp before just before I put it in the water. My digital thermomter on the front porch is reading 82-83 degrees.

To check accuracy, it's simple enough to make up an ice bath in an insulated container like a cooler or thermos and check the temp.

If it doesn't read 32, then use that as an offset. Of course the difference may not be totally linear, but for what we're doing, it's close enough.

If you want to go to an extreme, check it in a pot at a rolling boil. Altitude affects boiling temps, but you can find your altitude-adjusted boiling point temp on-line.

-RFL

Yesterday afternoon, 4/28 58*f at the surface in 3 different locations.