The knowledge of temperature effect on index properties and thus the understanding of its behavior is very essential for a complete understanding of the various cases of Geotechnical Engineering problems and for conducting practical research, analysis, and design in tropical regions, just like the Ethiopian environment. Seasonal variations, environmental effects, terrain challenges, and temperature effects all affect the qualities of soil. Simada is a city which is found in south Gondar and it is developing rapidly by construction . Rapid urbanization in the city area has led to an increased interest in the basic properties of soils that are present within the city area. There has been no previous documented research that looks into the effect of temperature on the investigation of index property of clay soil in Simada. This work focuses mainly on investigating the Index and some other properties of soil in Simada Town with varying temperatures. To explore the influence of temperature change, samples were collected from various regions of the city, and routine laboratory tests were performed on the collected samples at various temperatures. Disturbed samples were taken at an average depth of 1.5-2m depths below natural ground level. The standard laboratory tests performed on all twenty-four soils samples were the water content, gradation analysis, Atterberg limits, specific gravity, and compaction test. All specimens were tested at different temperatures having (25°C, 35 °C, 45 °C, 65 °C,75 and 105 °C). The variation of the plasticity characteristics of the soils has been determined based on the temperature variation. From the test result, we can conclude that temperature has a significant effect on the index properties of clay soil in our case red clay soil. Therefore natural soil with little drying should be used as possible for determining index property. Keywords: Temperature, Air-dried, Oven-dried, Soils Index properties, Compaction test.