晴はれ一いち時じ小こ雨さめ

Meanings

1

noun

clear with brief light rain

Weather forecast term indicating predominantly clear skies with a short period of light rain.

little, small

雨rain

晴はれ
晴れ simply means 'clear weather', while 晴一時小雨 specifies a temporary light rain during an otherwise clear period.
小こ雨さめ
小雨 means 'light rain' in general, whereas 晴一時小雨 is a specific forecast phrase combining clear weather and brief light rain.

Compound of 晴 (clear weather), 一時 (temporary), and 小雨 (light rain), forming a set phrase used in weather forecasts.