Longview Heights is located at 46°10′56″N 122°57′14″W (46.182099, -122.954006).
According to the United States Census Bureau, the CDP has a total area of 4.3 square miles (11.1 km²), of which, 4.2 square miles (11.0 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.93%) is water.
The climate is mild during summer when temperatures tend to be in the 60's and cold during winter when temperatures tend to be in the 40's.
The warmest month of the year is August with an average maximum temperature of 77.50 degrees Fahrenheit, while the coldest month of the year is January with an average minimum temperature of 33.80 degrees Fahrenheit.
Temperature variations between night and day tend to be moderate during summer with a difference that can reach 25 degrees Fahrenheit, and fairly limited during winter with an average difference of 14 degrees Fahrenheit.
The annual average precipitation at Longview is 48.02 Inches. Winter months tend to be wetter than summer months. The wettest month of the year is November with an average rainfall of 7.44 Inches.