When Is the Best Time to Sealcoat a Driveway in Maryland?
SealMaster's temperature rule for sealcoat, checked against NOAA climate normals for central Maryland.
SealMaster says sealcoat needs 50 degrees and rising for 24 hours with no rain expected. NOAA's 1991 to 2020 normals for BWI airport put the average daily low at or above 50 degrees from May through September (53.3 in May, 58.8 in September), which makes those the months that meet the rule on an average day.
The temperature rule
SealMaster, a pavement sealer manufacturer, says you must have 50 degrees and rising for a 24-hour period to apply sealcoat, and that it should not be applied if rain is imminent within 24 hours. Its E-Z Stir instructions say temperatures must be above 50 degrees both during application and for at least 24 hours after.
What Maryland's climate normals show
NOAA's 1991 to 2020 climate normals for Baltimore-Washington International airport put the average daily low at 43.6 degrees in April, 53.3 in May, 62.6 in June, 67.7 in July, 65.8 in August, 58.8 in September, 46.5 in October and 36.5 in November. On an average day, May through September are the months when the overnight low stays at or above SealMaster's 50 degrees. Individual days vary, so the forecast for the 24 hours after sealing is what counts.
Crack filling runs on a different calendar
SealMaster says hot rubberized crack sealant is ideally applied when the air temperature is between 45 and 65 degrees in areas with cold winters, because cracks open wider in cooler weather, and that hot-pour material can go down as low as 40 degrees.
Keep reading
Frequently Asked Questions
SealMaster requires 50 degrees and rising for 24 hours. NOAA normals for BWI airport put the average daily low at or above 50 degrees from May through September.
NOAA's normal daily low at BWI airport in October is 46.5 degrees, below SealMaster's 50-degree rule, so it depends on the forecast for the specific 24 hours after sealing.
Sources
The figures on this page come from these sources, read on 2026-09-25. None of them is South State Paving's own claim.
- SealMaster, Sealcoating FAQ
- SealMaster, E-Z Stir Pavement Sealer, application instructions
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020, monthly, Baltimore-Washington International Airport (USW00093721)
- SealMaster, How to repair cracks in asphalt pavement