Both ends of the thermometer
Some places give a painter one main weather problem. NOAA's engineering weather data for Greenville/Spartanburg points to two: freezing that works on joints and wood in the cold months, and humid hours that slow drying in the warm ones. A good exterior plan has an answer for each.
Freeze-thaw and what it opens up
NOAA's data for Greenville/Spartanburg lists about 47 freeze-thaw cycles in an average year. A cycle happens when the temperature drops below freezing and rises above it again. Water sitting in a crack expands as it freezes and opens the crack a little further.
On a painted house, look for the results at:
- caulk joints that have split or pulled away from one side;
- the ends of siding boards and the bottom edges of trim;
- window sills and the joints under them;
- painted masonry, where small cracks can spall.
Prep for these spots means cutting out failed caulk rather than caulking over it, letting wet wood dry before priming, and using a sealant rated for the movement a joint sees. The exterior painting page explains which gaps should be sealed and which left open.
Humid hours and drying
In an average year at Greenville/Spartanburg, NOAA counts about 656 hours with the wet-bulb temperature above 73°F and about 2,262 hours above 67°F. Wet-bulb readings that high mean the air is already carrying a lot of moisture, so a fresh coat gives up its water slowly.
For you, that means:
- the time between coats may run longer than the can says;
- crews often stop painting in time for the coat to set before evening dew;
- shaded walls can grow mildew, which has to be washed off and dried before painting.
Rain rate and planning
The same NOAA data lists a 100-year rainfall rate of 4.0 inches per hour. That's a design value for rare storms. For a painter, it's a reason to watch for afternoon storms, coat in sections that can be finished, and never start a wall that can't set before rain arrives.
Fitting the two limits together
Put the cold and the damp side by side and the comfortable days for exterior paint are the ones with mild, dry mornings and no rain in the forecast. A painter can't control the weather, but they can:
- start on the sunny side after a cold night, once surfaces are dry and above the label's minimum;
- stop early on humid days;
- use products whose labels allow lower temperatures or faster rain resistance when the season calls for it;
- tell you up front how weather days affect the finish date.
Ask how they choose which days to paint. Our pricing guide covers timing and the other things that move a quote.
South Carolina's registration rule
South Carolina's Code of Laws, Section 40-59-20, lists painters and wall paperers among residential specialty contractors, who must hold a Residential Builders Commission registration when the work on a home exceeds the figure in the card below. If you want, ask the painter whether they're registered. We don't check.
For the estimate visit
- Which caulk joints will you cut out and redo?
- How do you decide a cold morning is warm enough to start?
- What's your plan for humid afternoons?
- How will weather days change the schedule and the price?