Average Weather in Stephenville Texas, United States. In Stephenville, the summers are hot and muggy, the winters are cold and windy, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 35Â°F to 94Â°F and is rarely below 23Â°F or above 100Â°F.
Due to the moderating effect of the ocean, temperatures are cooler than more inland areas of Orange County, where temperatures frequently exceed 90 Â°F (32 Â°C) and occasionally reach 100 Â°F (38 Â°C). The period of November through March is somewhat rainy, as shown in the table to right.
The annual rainfall is sparse, only 50 to 400mm per annum. In January, afternoon temperatures usually range from 34 to 40Âº C. In 1939 an all time high of 47.8Âº C was recorded at the Orange River. Summer temperatures often top the 40Âº C mark. Winter days are warm.uch of the eastern Highveld, in contrast, receives 500 millimeters to 900 millimeters of rainfall per year; occasionally, rainfall there exceeds 2,000 millimeters. A large area of the center of the country receives about 400 millimeters of rain, on average, and there are wide variations closer to the coast.