Several parts combine into one character.

霜 is a phonetic-semantic compound: 雨 (rain) + 相 (xiāng, "mutual / each other" — providing the sound). The composite reads as "what falls from the sky and crystallizes by mutually matching grain" = frost. The character takes its place in the 雨 (rain) family of atmospheric phenomena: 雷 (thunder), 雪 (snow), 雲 (cloud), 霜 (frost), 露 (dew), 霧 (fog). All things that fall or condense from the sky live under the same rain radical.

Like many weather words in CJK, 霜 carries metaphorical weight: frost as the mark of years passing, the trials that whiten one's hair, the hardship of life endured.

Korean reading "sang." 霜降 (sanggang, "Frost Descent" — one of the 24 solar terms in the lunar calendar, falling around October 23 and marking the first frosts of autumn), 風霜 (pungsang, "wind and frost" = hardships of life — used poetically for the trials of years: "to weather hardships"), 秋霜 (chusang, autumn frost), 霜害 (sanghae, frost damage to crops — agricultural concern).

Mandarin shuāng, 1st tone. 霜 (shuāng, frost), 霜降 (shuāngjiàng, the Frost Descent solar term — observed in Chinese tradition), 结霜 (jiéshuāng, "to tie frost" = to form frost on a surface), 风霜 (fēngshuāng, hardships — same metaphorical use as Korean), 飞霜 (fēishuāng, falling frost — poetic). Tang dynasty poetry is saturated with 霜 imagery: 月落乌啼霜满天 ("the moon sets, crows cry, frost fills the sky") opens one of Zhang Ji's most famous lines.

Japanese on-reading ソウ (sō) — 霜降 (sōkō, the Frost Descent solar term — observed in traditional Japanese calendars), 風霜 (fūsō, hardships). Kun-reading しも (shimo, frost) — 霜 (shimo), 初霜 (hatsushimo, "first frost" — a noted seasonal marker), 霜柱 (shimobashira, "frost pillars" = the columns of frozen earth that rise from cold ground). And the most distinctive Japanese culinary use: 霜降り (shimofuri, "frost-falling" = marbling in beef — the white veins of fat that resemble frost on red meat). 霜降り肉 (shimofuri-niku) is the prized marbled wagyu beef advertised at high-end Japanese steakhouses; the term elevates the meat's appearance to seasonal poetry.

Memory aid: rain (雨) plus mutual (相 just for sound) — what falls from the sky and crystallizes by matching grain to grain.