Winters in Keller are typically mild, with average temperatures ranging from around freezing to the mid-teens Celsius, though occasional colder snaps can bring temperatures down into negative digits. Spring arrives in late March or early April, bringing temperatures steadily upwards towards the mid-twenties. Summer is warm and dry, with temperatures often reaching highs of over 30 degrees Celsius. Autumn is mild and pleasant, with temperatures gradually cooling as winter approaches once more.