As previously discussed, proper compaction is the most crucial element of ensuring quality asphalt installation. The various stages of compaction – breakdown rolling at high temps (high 200’s), intermediate rolling at medium temps (low to mid 200’s), and finish rolling at cooler temps approaching cessation temperature (150-200) are critical. Factors such as wind speed, sun/UV exposure, air temperature, ground temperature, thickness of asphalt, distance to the asphalt plant, and others relate to how fast the asphalt will cool once place and how much time is available for compaction. During summer months when placing a 4” section with a paver, for example, conditions are right and generally make compacting new asphalt much easier to manage. In winter months, placing a thin section of asphalt requiring a lot of handwork on a cool, breezy, cloudy day at a site far from the asphalt plant may make proper compaction extremely difficult.  In terms of precipitation, some mist, fog and even drizzle generally aren’t detrimental to quality but a steady rain should absolutely be avoided.