It would be very realistic if for example you had instead of an abrupt change in temperature when walking from biome to biome if you instead made it to where the temperature gradually changes or mixes. For example if you have a cold biome on an island and it's surrounded by an ocean then the temperature would be moderated by the surrounding ocean body. This would add new realism to the mod and would make sense as in real life whenever you have a biome that's isolated and is not exposed to any bodies of water than you could have extremes in temperature. MICROCLIMATES!