What's wrong with my Nellie Moser?

This is my Nellie Moser just a few minutes ago. I noticed it drooping yesterday so I watered it well around noon. We also had about 3/10 inch of rain.
It's appearance did not improve during the daylight hours, but it looked almost normal early this morning. It is on the south side of a wall, but gets a several hours of shade each day.
Last week, it looked great.
What can it be?
Temps here are high 70's to low 80's in the day time, temperatures in the 50's at night. Climate here is quite dry. Altitude is 7300 ft.
Any suggestions?

Here is the same vine on May 30, less than 1 week ago.

Now the picture.

Here is what it looked like the next day, May 31.

There is sometype of soil virus that causes "Clematis wilt". I lost my double blooming white unknown clem. cultivar this early spring. I didn't know what to do, but nipped off those wilted vine. Thanks goodness, new sprouts are coming up from the base.
With the altitude on your climate, clematis has some problem adjusting also. My daughter lives in Albuquerque and her clem. that I sent to her is not thriving just like that of "Red Bird of Paradise" that does well in your zone 7b, and not growing, developing as it should in my zone; also 7b.
Kim

P.S. let's hear/see others' experiences.

Just read through Plant Files on Nelly Moser and found that it needs mulch on the bottom. At first I will try that. But it is not at all hot here.

I began a web search on Clematis diseases and found the following article on Clematis Wilt:

http://gardening.wsu.edu/column/07-23-00.htm

It sounds exactly like what my plant ( which is just about 1 year old) is doing. I will follow the article's suggestions and cut it down to the ground in hope that it will come back. Sigh. It was just starting to get so pretty and had many buds.

It should return as mine did. Cheers! Thanks for sharing the link.

Your clematis looks like it is suffering from not getting enough water..the pic with the leaves and the flower drooping ..is telling you "water me"..Clematis need to have their roots stay moist..NOT SOGGY ...but moist...you said you are in an arid climate..so water water and add some mulch around so the soil can retain it's moisture...if it was wilt..it would all shrivel up and turn black...Jeanne

Thanks. I did water a great deal yesterday and we had 3/10 inches of rain. The soil appears moist. It just looks wilted. I will wait and see if it turns black before I cut it down.

Was the soil dry before you watered it the first time? If it experienced a bad enough drought stress to damage the roots, its recovery will not be as fast when it is watered again. That it recovered briefly makes me think this is the case. If so, my suggestion would be to cover it in some way to shade it and perhaps let it catch up. I've seen very similar symptoms in a Clematis whose main stems at the base were damaged.
Good luck,
Kenton

Its wilting for one reason only............. The altitude!!!!!!!!
The soil is probably not warm enough for it yet with you being that high up. The plant will be ok once it gets some new roots shooting!!
I dont know if you get the sun on it in the morning or not, but if you dont, and it gets the afternoon sun all of as sudden, it will cook from the reflection of the white wall you have it against. If this is the case shade it a little until it gets established.