Gonen and its surroundings are under the influence of the Mediterranean and Black Sea climates. As there is no natural barrier in the north  of the sea of Marmara  effect is seen. In the area where transitional climate characteristics are dominant, summers are hot and winters are rainy. In the surrounding high areas, the climate has slightly more continental influences. The annual average temperature in Gonen is 13.9 °C. The highest recorded temperature was 42.7 °C, observed on August 22, 1977. The lowest temperature was recorded on February 21, 1985 with -10.1 °C. The average precipitation is 657 millimeters. The vegetation is developed according to the climatic conditions, and the forested areas in the west and south cover a large area. Under the forest and in the destroyed areas, bush and maquis communities are seen. The tree species that make up the forest include oak, hornbeam and beech. Other tree species are maple, alder, linden, chestnut and red pine. The most common shrub and maquis elements are; maple, melengic, kermez oak, tar juniper, rosary bush.