<div class="eI2">Cloud cover (low,middle,high,total)</div> Clouds are vertically divided into three levels: low, middle, and high. Each level is defined by the range of levels at which each type of clouds typically appears.<br><br> <table border="0" cellpadding="2" cellspacing="2" style="width:100%"> <tbody><tr> <th>Level</th> <th>Polar Region</th> <th>Temperate Region</th> <th>Tropical Region</th> </tr> <tr align="center"> <th align="left">High Clouds</th> <td >10,000-25,000 ft<br>(3-8 km)</td> <td>16,500-40,000 ft<br>(5-13 km)</td> <td>20,000-60,000 ft<br>(6-18 km)</td> </tr> <tr align="center"> <th align="left">Middle Clouds</th> <td>6,500-13,000 ft<br>(2-4 km)</td> <td>6,500-23,000 ft<br>(2-7 km)</td> <td>6,500-25,000 ft<br>(2-8 km)</td> </tr> <tr class="even" align="center"> <th align="left">Low Clouds</th> <td>Surface-6,500 ft<br>(0-2 km)</td> <td>Surface-6,500 ft<br>(0-2 km)</td> <td>Surface-6,500 ft<br>(0-2 km)</td> </tr> </tbody></table> <br><br>The types of clouds are:<br><br> High clouds: Cirrus (Ci), Cirrocumulus (Cc), and Cirrostratus (Cs). They are typically thin and white in appearance, but can appear in a magnificent array of colors when the sun is low on the horizon.<br><br> Middle clouds: Altocumulus (Ac), Altostratus (As). They are composed primarily of water droplets, however, they can also be composed of ice crystals when temperatures are low enough.<br><br> Low clouds: Cumulus (Cu), Stratocumulus (Sc), Stratus (St), and Cumulonimbus (Cb) are low clouds composed of water droplets. <br> </div>