also: ねんこうさ
noun
annual range; yearly range
Meteorological term for the difference between the highest and lowest values of a climatic element (especially temperature) within a year.
この地域の気温の年較差は大きい。
The annual range of temperature in this region is large.
年較差が小さい海洋性気候では、夏と冬の気温差が少ない。
In an oceanic climate with a small annual range, the temperature difference between summer and winter is small.
日較差 refers to the daily range (difference between day and night), while 年較差 refers to the annual range.
Compound of 年 (year) and 較差 (range, difference). The reading ねんかくさ is standard; ねんこうさ is a less common variant.