1 Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.  A chemical substance is composed of one type of atom or molecule.
February (Inca Trail Closed) 1  Overview: Another wet month, and not the best time to visit to Machu Picchu. 2  Temperature: Daytime average highs are around 20 degree C (68F) and night time average lows around 8C (46F) 3  Humidity: Average daily relative humidity is around 66 %.
This is particularly relevant during the months of January and February when the rainfall is at its heaviest. There are two main areas where problems frequently occur: 1) on the trains to Machu Picchu, 2) domestic flights in and out of Cusco (see below for more information).