For example, when perihelion falls in January the northern hemisphere winter and southern hemisphere summer are slightly warmer than the corresponding seasons in the opposite hemispheres.
(perihelion; falls; T:in January) (the northern hemisphere winter and southern hemisphere summer; are; slightly warmer than the corresponding seasons in the opposite hemispheres; T:when perihelion falls in January)
perihelion the northern hemisphere winter and southern hemisphere summer
falls are
T:in January
slightly warmer than the corresponding seasons in the opposite hemispheres T:when perihelion falls in January