spiders don't hurt plants, in fact they eat bugs that eat plants.

They are likely spider mites and they are not something you want eating your plants. The usual (non-chemical) remedy is increased humidity (spray the plants a couple times a day with the hose).

There are a number of chemical controls. For really problematic infestations a systemic can be used (though I do not know if Clematis are adversely affected by systemic pesticides).

~Chills

Spider mites are not common outdoor pests in WA and OR.

Damage to the plants would be noticeable long before one would see the mites which are very very small, usually require magnification to indentify as red spider mites.

If the plant is lush and healthy it doesn't have spider mites. They cause a plant to look sickly and pale.

I too have red spiders, however they are on a healty aloe vera plant, and the webs are everywhere also. What can I do to get rid of them?

If they are spiders, sevin would do the trick. However, if they are doing no harm, why bother with them?

At this time of year in the PNW, various spiders and their webs are EVERYWHERE! I can't even walk out my front door and to my gate without encountering a dozen or so new webs every morning. It is entirely normal and very natural and I would encourage you do nothing - spiders are some of the most beneficial of the insect residents of our gardens and although walking into a web is not my favorite activity, I try to co-exist with these very helpful creepy crawlers :-)

As BOS has noted, it is not likely these are spider mites. Spider mites prefer very dry environments (which our "summer" has not provided), their webs are tiny and unlike the the typical netted, circular web of a true spider and they are indeed invisible to the naked eye. It is far more likely you would encounter problems with spider mites (a mite, not a spider at all) growing a clematis as an indoor plant rather than outdoors, as the low humidity indoors encourages their populations.

I found a very informative article on wikipedia here
http://en.wikipedia.org/wiki/Spider_mite

I noticed them today near a bus stop in downtown Portland, OR. Once my eyes focused I could see countless amounts of them all over everything. I thought they were bloodsucking parasites so I rushed home and looked it up.

They suck the juices from the leaves of plants. The damage to the plants are caused by the sheer numbers of them. Chemicals don't appear to work on them. They breed so much that they eventually adapt to insecticides.
They don't like coldness or wetness so I agree with Chills advice. They'll probably leave as soon as we get our good old fashioned NW weather back.

Here is a link that might be useful: Spider mite Wikipedia

What you saw where baby spiders, not spider mites. I have red baby spiders all over my yard right now too. They do no harm, spiders eat aphids and mosquitoes. I welcome them.

Spider mites are not common here and certainly not this early this year after all that rain.

Spider mites cause damage that you can easily see long before you can see their webs and the mites themselves which are almost microscopic.

When I go to Phoenix or Palm Springs I can see spider mite damage from the car driving around town, they are very common there and very easy to spot their damage. Not something I ever see here except in my greenhouse where I brought them in on a houseplant and even then they are not red. They are green because they are two spotted spider mites.

Spider mites are always found underneath the leaves they are on and not out in plain sight where you could see them without a magnifying glass.

The post you answered is four years old.

Spider mites can be controlled but it can be difficult in hot dry areas where they are common.

Not knowing what your pest is and just spraying willy nilly is a really really bad idea. People, pets and wildlife are poisoned by insecticides and fungicides sprayed incorrectly all the time. I wish they would ban more of them than they have already. It is scary how few people read labels and follow them and really know what they are doing.

I've noticed a small insect on our pool deck in Palm springs. There are a lot of them turning crazy quick circles in the sun, and about the size of pin point. they are hard to see but appear to be a fleshy orange color. Are they possibly spider mites? We have no vegetation, but our neighbors over the wall do.

No, spider mites would be on plants not on your pool deck.