Based on the Köppen climate classification, Mount Eglinton is located in a marine west coast climate zone. Prevailing westerly winds blow moist air from the Tasman Sea onto the mountain, where the air is forced upward by the mountains, causing moisture to drop in the form of prodigious rain. The months of December through February offer the most favourable weather for viewing or climbing this peak. Climate data for Eglinton Knobs Flat which is five kilometres north-northeast of Mount Eglinton: