Belonging to spring, or happening in spring. It is a formal, written word, and in modern English it survives mainly inside a few fixed phrases.

Belonging to spring屬於春天的， or happening in spring或發生在春天的。It is a formal, written word這是個正式、書面的字， and in modern English在現代英語裡 it survives mainly inside a few fixed phrases主要只活在少數幾個固定用語裡。

The commonest by far is the vernal equinox — the day in late March when day and night are about the same length and spring officially begins in the northern half of the world. You will also meet vernal pools (shallow ponds that fill with rain in spring and dry up later, important for frogs), and in botany, plants described as vernal because they flower in spring.

The commonest by far is目前最常見的是 the vernal equinox vernal equinox（春分） — the day in late March三月底的那一天 when day and night are about the same length日夜差不多長 and spring officially begins in the northern half of the world北半球正式進入春天。You will also meet你也會遇到 vernal pools vernal pools (shallow ponds that fill with rain in spring and dry up later春季小水塘，被春雨填滿、之後乾涸， important for frogs對青蛙很重要)， and in botany還有在植物學裡， plants described as vernal因為春天開花而被稱為vernal的植物 because they flower in spring。

Outside science, poets use it more freely and more loosely: vernal air, vernal green, and by extension a vernal freshness in a person — meaning young, new, full of beginning. That second use is a stretch of the first, and it sounds deliberately literary.

Outside science在科學以外， poets use it more freely and more loosely詩人會更自由、更寬鬆地用它： vernal air vernal air, vernal green vernal green, and by extension延伸出去 a vernal freshness in a person也可以形容一個人身上的vernal freshness — meaning young, new, full of beginning意思是年輕、嶄新、充滿起頭的感覺。That second use is a stretch of the first這第二種用法是從第一種延伸出來的， and it sounds deliberately literary聽起來刻意帶著文學味。

In everyday speech nobody says 'vernal weather'; they say 'spring weather'. So: read it as 'spring-', and when you write, use it for the equinox and for scientific contexts, and let plain 'spring' do the rest.

In everyday speech在日常口語裡 nobody says沒有人會說 'vernal weather'『vernal weather』； they say大家會說 'spring weather'『spring weather』。So所以： read it as把它讀成 'spring-'『春-』， and when you write寫作時， use it for the equinox and for scientific contexts用在equinox和科學情境裡， and let plain 'spring' do the rest其他的就交給普通的『spring』就好。