Can the max water temperature (of a sea or lake) be higher than the average air temperature in the hottest month. (climate, averages)

[Weidehond]

Interesting question. I think the answer is Yes. The albedo of water is dirrerent as the albedo of a land surface. When the sun is high in the sky, the albedo of water is very low. That means that a water body will absorb more warmth than a land surface (especially in summer). So when the circumstances are good, the answer could be yes!

[miamihurricane555]

the average temp for the ocean is warmer than the average for air in every month here in S>FL though one could argue that the warm gulf stream is the reason for that.

[ase42dv]

Yes for a few days.

Actually, about 100km north of my zone in the last week of November happened a watersprout because the water was warmer than the air.



21.5ºC (70,7F) had the water in 27th of November, while the outdoor temperature was of 17.5ºC (63,5F)




Although the warmest without doubts was in mid August of 2015, when the sea temperature reached almost 31ºC (87,8F) in the Dénia area (38.5ºN, Mediterranean Sea) while outside was raining with 26ºC (78,8F):

[Baba_Wethu]

It's pretty simple really why it would happen. Average water temperature should almost always be higher than average air temperature because air isn't heated (much) by the sun; it's heated by the ground. Water, on the other hand, is the ground. Water will not heat as much or as quickly as land, but it will heat up more than air at least.
Let's say we have a small lake in northern Sweden in July. Average air temp might be 17'C for a few weeks, but that's in the air, not in the sun. The lake however, will have a "baseline temperature" equal to the air temperature (just like a glass of water will turn to room temperature after a while), but it also has the sun shining on it which means temperatures might never even sink below 18-20'C.

The heat capacity is much higher than that of air or land though, so water will have less diurnal range and thus the average high temperature of the water can be lower than that of the air, but the mean will pretty much always be higher.

[ScottsdaleMark]

Originally Posted by Weidehond

Interesting question. I think the answer is Yes. The albedo of water is dirrerent as the albedo of a land surface. When the sun is high in the sky, the albedo of water is very low. That means that a water body will absorb more warmth than a land surface (especially in summer). So when the circumstances are good, the answer could be yes!

Exactly.

The depth of the water matters quite a bit. A shallow lake or pond will heat up all the way through much quicker than a deep one will because there is less water and more of the water is being affected by the solar heating (e.g. close enough to the surface to be warmed by the sun).

The clarity of the water might matter somewhat as well but I'm not 100% on that...clear water would have rays go deeper/farther than water full of contaminants which would prevent the rays from going as far; however, the contaminants (e.g. plants, detritus, whatever) also absorb heat, so there would still be some impact. So this effect is probably not that important.

There are places in Canada as mentioned, but also up in Alaska, e.g. Chena Lakes, where the water can get quite comfortable, even warm, during the height of summer. In that case, it's a very shallow lake created as part of a flood control project. It's pretty awesome.

[Cambium]

Water temp takes time to change. Land is influenced by much more.
Water temps off the coast here is 50s in Fall while the average temp is 40s. This is not only because water takes time to cool off but also because nightime Lows over land can drop the Average a lot.

Ever see how slow a pot of boiling water takes to cool down?

[unobtainium]

Jumping into water that is warmer than the current air temp is one of the nicest feelings in existence. I mean, unless the air temp is like 45 and the water is 50 or something.

[Cambium]

Originally Posted by unobtainium

Jumping into water that is warmer than the current air temp is one of the nicest feelings in existence. I mean, unless the air temp is like 45 and the water is 50 or something.

I dont know, Im not a fan of saunas because of the uncomfortable feeling you get coming out of the warm water. going in feels good though.

I prefer going in cool water on a hot day vs warm water on a cool day.

*That would be an interesting poll to do

[cBach]

I think up north because summertime has longer daylight hours the bodies of water can heat up if the sun is shining directly for long periods of time. The night still cools off quickly so the average air temp is lower than the water.

In the south the average air temperature can be north of 90F (75/105 let's say) but the water temperature rarely gets that high. Usually it peaks out around 88F in August and if you're swimming in mid-day you still get a 27F decrease in temp if you jump into the lake. The air temp approaches 75F at say 5AM but it's usually still 90+ at midnight some nights. So even at midnight the lake (or Gulf) feels cooler than the air. With the wind when you step out you can still feel quite cool but the air temp is still warmer than the water.

So I think this only applies up north. The water is almost always cooler down south, except in the fall and winter. In fall it's not uncommon to still have 80F water temps and 70F air temps. I've gone swimming comfortably in November. In the spring the water takes forever to heat up, you can have 95F temps in May and 68F water temps which are too cool for me. Warm water is more important than warm air.

[memph]

Lake of the Woods has an average water temperature of 71F (21.5C) in July.
https://lakemonster.com/lake/MN/Lake-of-the-Woods-307

Thunder Bay and Red Lake, ON have daily means peaking at 18C, and White River, ON only 16C, but I've been swimming in lakes in all those areas in August, sometimes even late September, and the water was not cold. By not cold, I mean 20-25C - they definitely felt warmer than Lake Superior which only reaches 18-20C in the warmest shallow bays in late August. Night-time temperatures are around 11-12C, and days reach 20-25C typically. I would be curious to see if some of the lakes near Wawa and White River get warmer than the average day-time highs, because the average highs are only 20-22C, yet small lakes and surface water fed rivers feel at least that warm, if not slightly warmer (maybe only the top 50cm of water that you swim in though - and I guess I also tend to swim in them on warm sunny afternoons rather than cool overcast mornings).