Does salt affect the temperature of water?

YesThe presence of any solute in water has the effect of lowering its freezing point and raising its boiling point. More salt will cause this effect to be greater.

Why it does that is complex, but below is a pretty good description.

The following is taken from the site listed to the left of this answer, but that page has a lot of additional information, and this is the most important part. This is the real reason the vapor pressure of salt solutions are decreased:

"The reason dissolved solutes (such as salt) increase boiling point is that the solute must come out of solution in order for the water to boil. This costs entropy (the entropy of solution). Boiling is entropically driven, hence the reduction in the net entropy gain of boiling results in a higher temperature needed for the reaction to go. To put it without jargon: for a little packet of water with dissolved salt to turn to steam the salt atoms must, in the course of their random zooming about, ALL simultaneously leave the packet. This is not a likely event. It becomes more likely as the temperature (i.e. the average speed of zooming about) becomes higher, though, and at a certain temperature above the ordinary boiling point it becomes sufficiently likely to allow boiling in spite of the handicap. You can also see that the effect will naturally increase with the concentration of dissolved solutes (i.e. the number of salt atoms per packet that must simultaneously leave)."

Salt will increase the boiling temperature of water.

If you dissolve 1 mole (58.43 g) of NaCl in 1 kg of pure water the resulting solution will boil at 101.04°C.