Complex sentence: As with much of the Pacific Northwest west of the Cascades, Portland experiences a temperate oceanic climate typified by warm, dry summers and mild, damp winters; the city proper straddles the border between USDA Plant Hardiness Zones 8b and 9a.
Split into simpler sentences: As with much of the Pacific Northwest west of the Cascade Mountains, Portland experiences a temperate oceanic climate typified by warm, dry summers and mild, damp winters. The city proper straddles the border between USDA Plant Hardiness Zones 8b and 9a.