The annual average temperature in Vancouver is 11.0 °C (51.8 °F) downtown and 10.1 °C (50.2 °F) at the Airport, in Richmond, amongst the warmest in Canada. It is located in a USDA plant hardiness zone of 8 , similar to other coastal or near-costal cities such as Seattle, Portland, Amsterdam and London, as well as places such as Atlanta, Georgia and Raleigh, North Carolina, far to the south. The mild climate allows plants such as the Windmill Palm to sustain. Vancouver's growing season averages 221 days, from March 29 until November 5. This is 72 days longer than Toronto's, and longer than any other major centre in Canada.