The conditions in the Otherworld do not always match those of our reality, in geology, geography or seasonal variation. While it seems to share the same overall temperate climate and resultant ecology, Unnatural Resources make note of the following:
There are no such things as seasons as we recognise them. More precisely the plants and animals appear to be having all the seasons, all the time. At any given time, a proportion of the Otherworld population will be experiencing Spring growth, while others will be in Summer plenty, some in Autumn decline and the rest in Winter dormancy. It is theorised that the Lust exists because of a continual Spring-like drive to procreate in order to take advantage of the Summer plenty.
In addition to this, the weather is extremely changeable to the point where Expeditions can find themselves in a Summer-like heatwave followed by a Winter-like blizzard and back within the space of a few days. This variety is most often seen in locations like the Isle of Apples, which can be a hill on a plain, a marsh, a lake, or even a sea, depending on the conditions at the time.
The Otherworld life seems to adjust to these sudden extremes and take no harm from sudden frosts or equally sudden heat. However, the typical temperatures and weather are actually more similar to our own – wet, temperate and mild – just not necessarily when expected or desired.