When applying a sealer or coating to exterior concrete in the Fall or Winter, temperatures can drop pretty drastically overnight. For this reason, you want to apply the sealer in the early afternoon, instead of the late afternoon or early evening allowing the sealer more time to cure while the temperatures are elevated during the day. This time of the year, sun positioning will not be a concern as the sun remains lower in the sky and is more indirect. In order for a sealer or coating to properly cure, it needs to be applied when temperatures ranges will remain between 55-85 degrees Fahrenheit during the time of application, and until it fully cures. This means that for at least 24 hours temperatures should not drop below 55 degrees Fahrenheit, and they can’t exceed 85 degrees Fahrenheit.
While penetrating sealers like the Armor SX5000 and Armor SX5000 WB will dry within a couple of hours, acrylic sealers like the Armor AR350 and Armor WB25 need at least a full 24 hours to properly cure. Applying an acrylic when the temperatures are too cold will prolong the curing process and could keep the acrylic in a semi-liquid form.