There are three distinct seasons offering varied conditions. The cold season (Nov-Feb), with temperatures ranging from 15 to 28 Celsius, is the most comfortable for hiking and camping. You'll want to bring some warm clothes such as a light jacket or sweater as the evenings and early mornings can be quite cool; layer so that you can peel down to cooler clothes as the day warms up. The hot season (Mar-May) temperatures range between 27 to 32 Celsius. This means playing in the waterfalls is a must. Brings clothes for wading or swimming.

The fertile forests are made up of hill evergreen forest, moist evergreen forest, mixed deciduous forest and dry dipterocarp forest.

The rainy season (Jun-Oct), easily the most beautiful, brings forth a burst of green; as well as a healthy population of insects. This is my favorite time when the forest is at its most colorful. Be prepared to get wet and enjoy the rain forest in all its glory. The waterfalls are at their most beautiful, but this is not the time for playing in them. Bring your bug spray! Temperatures range between 24 to 30 Celsius.

Some species of fauna living in the national park are common muntjak, common wild boar, palm civet, civet, Malayan flying lemur, macaques, tiger, black cat, barking deer, flying squirrels, Siamese hare, common red jungle fowl and more than two hundred confirmed species of birds such as vernal hanging parrot, partridge, Richard's pipit, sooty - headed bulbul and blue - winged pitta. Doi Luang is also known to have a rich source of mixed deciduous forest, decidious dipterocarp and evergreen forest that blankets the national park with various kinds of tree, bamboo and plant.

While many visit Doi Luang to trek in the vast forest-covered mountains or visit hill-tribe villages, most visitors come to this park for the magnificent waterfalls. Pu Gaeng Waterfall features limestone and travertine deposits that give this waterfall its characteristic steps or levels. There are a total of nine levels, it is said the most beautiful are the fourth and the fifth, with a 1 km trail through the tropical forest dominated by bamboo. From the camping ground to the second level, there is a natural trail that allows visitors to study nature close at hand. Another exciting route is the 1,500 meter path to the top of the fall, a vantage point to admire the whole area of Doi Luang, Payao province and Payao Lake.