How do they usually measure water temperature?

Factual Questions
1

I’m talking about swim sites, of course.

Cases in point:

  • A few days ago the Chicago Park District’s web site reported a 77-degree water temperature. At Osterman Beach it certainly wasn’t anywhere near that warm; in fact, the white board near the snack bar said 61 degrees…which sounded closer, but still too cold.

  • Last week my wife and I were in New Buffalo, Michigan. Sign claimed the water temperature was 51 degrees. Hmm…sure looked like a ton of people had an incredible tolerance for cold water! We stepped in the water, and it was bathtub-warm!

  • Jersey shore…my wife and I were at various beaches there last summer – Asbury Park, Ocean Grove, Seaside Heights (we’ve been going to Seaside every year since 1998, so no, it had nothing to do with that show I refuse to watch) – and despite reporting of temperatures in the 70s, it was too cold to go in, even for my water-rat wife who has a much higher tolerance than me.

So…what actually do they do?? Do they grab a bucket of water from that particular body of water, put it on the stove, then stick a thermometer in it? Do they usually check the temperature more than once a day at swim spots??? Do they take the temperature at multiple locations then calculate the average???

2

Incorrectly, by the look of your examples. :smiley:

3

I always loved how people say oh its only 98 here today. And I am like the fuck it is it is over 102, it may be 98 on top of your building news caster but in the suburbs with everyones big SUVs and hot engines and A/C pumping out it is A LOT hotter

4

Our government provides water temperatures at coastal beaches.

http://www.nodc.noaa.gov/dsdt/cwtg/egof.html

They don’t say where the data comes from. It’s current as of today.

update There’s a submit data button at the bottom of the page. They trust a bunch of surfer dudes to collect data. Kowabunga!

5

Chances are the measurements come from anchored buoys in the particular body of water.

6

This link is better. Click the map for the region you’re interested in. I just looked at Hawaii’s beach temps. Sure makes me want to jump on a plane and visit.

They even have the great lakes.
http://www.nodc.noaa.gov/dsdt/cwtg/index.html

7

Raw temperatures are not always much use anyway.

Standing still in a strong breeze at 22c in the shade you will feel a lot cooler than walking in the sun in otherwise still air at 16c even wearing the same clothing.

And a building that has dropped to 10c can still tend to feel cold even if you can raise the air temperature to 20c as long as you are near a solid wall that is still ~10c.

8

They have wireless pool thermometers for under $100. Floats in the water and transmits the reading to a Wireless Receiver located indoors, up to 328 ft. away.

http://www.amazon.com/gp/product/B001ED3IOW/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000W9QW6U&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1QGSA6ZZ4Q60P32QS2JK

The lifeguards at the beaches probably use something similar.

That would explain why the water seems colder. A floating thermometer gets surface temps. The water is colder even a few feet below the surface.