Seasonal ratings are used to describe the time of year and their corresponding temperatures, for which the sleeping bag is most suitable for comfort in terms of warmth:
Season 1 sleeping bags are suited to the warmer summer months where night time temperatures average 10pC.
Season 2 sleeping bags are suited to the months from late spring to early autumn where average night time temperatures are not much higher than 5pC.
Season 3 sleeping bags are suited to spring, summer and autumn where the average night time temperatures do not fall much below freezing point.
Season 4 sleeping bags are suited to the harsher winter months where temperatures average -5pC.
Season 5 sleeping bags are suited to extreme temperatures encountered on expeditions where night time temperatures may average -15pC.
These ratings are only intended to be a guide and temperatures can vary greatly for the seasons from the guide above according to the area, altitude, environment and each individual year. The seasonal rating is also intended to advise on the best sleeping bag for comfort and not for extreme capabilities where the rating would be a lower temperature. For a more exacting temperature recommendation, please refer to the individual product. The notion of what is warm may vary from person to person and this is also worth considering when choosing a sleeping bag.
