Sap is a vital part of the tree’s life as it carries important nutrients and water through the tree. There are several reasons why sap oozes from trees.

If it is disease, fungus or pests, you can look for presence of sawdust, small holes in the bark, or sap leaking from a single place in the bark. Some pest infestations can cause the sap to look like popcorn, or a have a pinkish tint. Certain diseases can also cause white patches of dry resin.

You can also look for sap coming from pruning cuts, broken branches from storms and mechanical injuries.

As you noted, the release of tree sap can also be temperature related. In early spring, while many trees are still dormant, the fluctuation of temperatures may affect the flow of tree sap. Cold/warm weather cycles can produce pressure within the tree, forcing sap to flow out through openings.

Also, at the tip of pine boughs, there is a bud where pine cones develop in the spring. This bud is protected by a resinous sap. In drought years, there is less of this resinous sap. In wetter years, there may be some excess sap that can drip from these buds.

Finally, sometimes the dripping that we see is not actually sap, but rather 'honeydew'. It is coming from aphid insects. They suck sap from the needles and excrete a liquid that is high in sugar and has a shiny appearance. Check the needles for small soft-bodied insects, and if found, a strong stream of water from a garden hose will dislodge them to reduce the level of feeding.

If none of these apply, you can take a sample to the Diagnostic Clinic at Arapahoe County Extension Office at 1690 W Littleton Blvd, Suite 300, Littleton, CO 80120; Phone:<personal data hidden>. There is a small diagnostic fee for in-county residents. Make sure the sample you bring is at least 18" long and is indicative of what exactly you are seeing on the tree.

As far as removal of sap, you would need to do some internet research. A local auto body shop may be able to direct you to a product that can remove sap without damaging paint. You can also try to protect other items with a tarp or painter's sheeting that can be disposed of.

Since you have pines in your landscape, here are some helpful links for you:
http://www.ext.colostate.edu/ptlk/1456.html
http://www.ext.colostate.edu/pubs/insect/05591.html
http://www.ext.colostate.edu/pubs/garden/02948.html
http://www.colostate.edu/Depts/CoopExt/4DMG/Trees/natever.htm
http://www.ext.colostate.edu/pubs/insect/05528.html