I failed 8th Grade Geology/Geography
 

So, this summer, I went to Egypt and it was hot hot hot! It's a neat place cause the desert is right next to the Nile so it's quite the trip. So, as you can imagine, it is very hot and dry there, especially in the summer. One day, I jumped in Nile and almost had a heart attack as the water was cold!! I mean really cold. It was awesome!! But weird as the sensation of being out of the water, hot and dry, then jumping in such cold water. It's also fairly clean to my surprise.

Anyways, my question is, how come the water is so cold when it is so damn hot (I mean 110-120 F or 40-50 C) all the time? The Dead Sea by contrast, was hot (and rather uncomfortable for me).

Part of what makes it seem cold would probably be the fact that it's so freaking hot. If the water was 75 degrees (pretty warm for water) then jumping into it from an air temp of 115 degrees would be quite the shock!

Also, if the river is deep, the deeper water is going to stay really cold, while the water on top is going to be warmer. You could have just jumped into a cold spot.

Where abouts on the nile did you go?

Down at luxor where i was the nile is like you describe, lovely. There is a difference between the air temp and water temp, as sage suggested. There is also the fact that the nile is pretty big, even at egypt temps it would take loads of energy to bring it up to warm temps.

I was curious, so I did some research.
Turns out that the Nile is mainly melted snow. The Nile begins in between west Ethiopia, and Southeastern Sudan. There are some very high alittitude mountains in Ethiopia, most of which are snow capped. Since you were their during the summer, you jumped into freshly melted snow from Ethiopia. This also contributes to the Nile's annual flooding
http://www.artsci.wustl.edu/~anthro/...le%20Delta.jpg
Snow melts from Ethiopia, then flows up out of Egypt into the Mediterranean

The nile doesn't flood anymore. The Aswan dam stopped that.

Thanksfor the explanations guys, it makes more sense and I feel more stoopid now.

Oh man, awesome satellite pic Ch'i. The Nile is 80 meters in some places and the current is fairly strong. I do undrestand the relative temperature thing but I go to tell you, the water was cold (shiver) but awesome! The fact that it was snow melt and rapid current and deep water makes sense.

I was up and down the Nile all over, I was in Lluxor too but I went in at Aswan, closer to the source I guess. Egypt was an awesome experience.

75 is pretty cold to me. I won't get in water that cold. It gets a few degrees cooler around Ft. Lauderdale in the dead of winter but climbs to the upper 80s by the end of July. Thus the power of hurricanes! And thanks to the Gulf currents. Which goes to another point: the water isn't neccesarily warm because of the climate of the air but due to the currents.

Of course, 75 in Michigan is quite warm, which must explain the northerners swimming in Florida in the winter.