Bricks, Masonry, Asphalt and Concrete - Using low VOC paint for exterior porch/step

I need to repaint my concrete porch and steps. An article in the Going Greener section said "the lack of glycol [in no VOC paint] makes it hard to get a good finish in an environment below 40 degrees". Does this mean if you are painting when it is less than 40 degrees or if you are painting in an area where the temperature goes below 40 degrees in the wintertime? I ask because I thought you weren't supposed to paint exterior concrete when the temperature is less than 50 degrees.

Not long ago most exterior latex paints could be applied only at temperatures above 50° F. In recent years, specially formulated paints and primers have been engineered for temperatures as low as 35°F (concrete surface). There is no longer a standard, now there's a roster. My advice to you is, whatever product you have been using stick with it. Read the instructions, all the specs of your product will be there. Use good common sense following the temperature guide lines. They will be different than the ones you read about. Wait for desirable conditions if you can.

I'm not familiar with any exterior low voc paints - they're usually coatings designed for interiors where air quality might be a concern. I would assume the article reffers to the temp the paint is applied in. Temps shouldn't be a big concern after the coating has dried/cured.