A 10.5 tog isn’t too light and isn’t overly warm — it sits in the middle-weight range. This makes it suitable for both cooler and milder nights, rather than being specialized for only winter or only spring season. tog rating for every season, suggesting that you don’t necessarily need to swap duvets when the seasons change. If your bedroom temperature fluctuates (for example, you have heating, or your house is well-insulated), a 10.5 tog duvet adapts reasonably well. What’s ideal depends a lot on whether you sleep hot or cold. Someone who overheats may find 10.5 tog too warm in summer; someone who feels the cold might still want something heavier in winter. The actual comfort you get from a 10.5 tog depends on how warm or cool your room is at night.