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    Four Ways Scorching Summer Heat Is Visible to the Eye

    By Katy Galimberti, AccuWeather.com Staff Writer
    July 2, 2014; 8:05 PM ET
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    Aside from feeling the heat in the summertime, heat also makes a visible presence when warmer weather occurs. As summer brings higher temperatures and more humidity, sometimes the season can create an uncomfortable mix. When temperatures peak to their highest levels, the pesky heat can become visible.

    Mirage/Wavy Lines on the Road

    When driving to your favorite summer vacation destination on a hot, steamy day, you may see wavy lines hovering over the road in front of you. On a hot surface, such as a sunny road, air will stand in layers of different densities.

    "The heat from the road will rise and the cooler air above the road will tend to sink," AccuWeather.com Meteorologist Mark Paquette said.

    When high heat interferes with normal air density, bright wavy lines appear on surfaces like sidewalks and roads like this highway in Death Valley. (Photo/Flickr/OliBac)

    Because warm air is not as dense as cool air, once summer hits and induces higher temperatures, the heat from the road rises and mixes other layers of warm and cool air. As a result, those layers appear as bright wavy lines.

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    "The sun's rays are much stronger in the summer. Basically, the differences in temperature between the road and the air in summer is much higher than in the winter," Paquette said.

    The rays from the sun travels through the warm and cool air at different temperatures, thus creating a mirage-like effect.

    "Steam" After Rain

    When rain falls as a refreshing relief from summer's heat, you may see something that looks like steam rising from a road or sidewalk.

    That "steam" is an evaporation that becomes visible when the rain makes contact with the heated pavement.

    The pavement itself becomes warmer than the air during hot summer days so after rain hits the pavement, it immediately evaporates. However, the surrounding air will have cooled down due to the cooler temperature of the water so "steam" then rises.

    "The pavement may be able to evaporate more water than the rain-cooled air can hold," Paquette said. "If that happens, the water condenses into the 'steam' or 'mist' you can see."


    Summer temperatures can make your drink "sweat." (Silvio Verrecchia/iStock/Thinkstock)

    Condensation, that "sweat" that forms on your water bottle, occurs more frequently in the summer due to higher temperatures on the outside of your drink. The water inside the bottle cools the surface below the air's dewpoint, creating the "sweat" effect on the container, Paquette said.

    Melting Roads

    Construction materials are heavily affected by high temperatures during and after the building process. Safety Director at the Ohio-based Great Lakes Construction Company Bill Hocevar explained that summer temperatures can be tricky for workers and the materials they work with.

    "When asphalt gets to 110, 120 and 130 F, you can see the heat wave coming up from it," he said. "When put down, it's extremely flexible pavement and becomes spongy like."

    After construction is completed, the consistency can still become pliable when heated to similar temperatures.

    In addition to asphalt, concrete has to be regulated during extreme heat. According to Hocevar, they often mix ice with concrete to keep it at a workable temperature.

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