Сам себе и отвечу, может кому то будет полезным (нашел на
https://greenlandtours.com, там еще много всего интересного):
What is the best time to travel to Greenland?
People travel in Greenland mainly in summer or winter. In summer season the best time to travel is from mid June to mid September. The winter season starts in November and lasts until the end of April. For a proper winter experience, however, we recommend travelling from mid February to mid April as there is greater likelihood of snow, more daylight and also more activities on offer.
What is not a good time for travelling in Greenland?
October, November, December and January as well as May are low-season months and less frequented. This is due to unstable weather with high winds, rain, snow and fog, which often results in flight delays or cancellations. During this time flight schedules to and within Greenland are reduced and excursions are hardly offered.