日射|にっしゃnissha[0]heiban (flat)

1. nounsolar radiation; insolation

• Synonym陽光ようこうWrittenWritten/formal prose with a literary flavor, as in 「春の陽光」.
• Synonym日差しひざしNeutralNeutral and common in daily speech; focuses on the feel of sunlight shining down.
• Synonym太陽放射たいようほうしゃWrittenWritten/formal prose; a scientific term for the energy the sun radiates, more technical than 「日射」.
• Related日光にっこうNeutralNeutral and common in daily speech; focuses on the sun's light itself, as in 「直射日光」.
• Related太陽光線たいようこうせんWrittenWritten/formal prose; centers on the rays themselves, mostly in scientific explanations.
• Related太陽光たいようこうNeutralNeutral; sunlight in general, as in 「太陽光発電」 or 「太陽光を浴びる」; 「日射」 is the more meteorological word, covering insolation and solar radiation.
• Antonym日陰ひかげNeutralNeutral; a spot where no sunlight reaches — the opposite of 「日射」, which implies the sun is shining.

Use 「日射」 for insolation or solar radiation in weather and medical terms like 「日射病」 and 「日射量」. For everyday sunshine pick 「日差し」 or 「日光」; 「太陽光」 is general sunlight, 「陽光」 is literary, 「太陽放射」 scientific, and 「日陰」 is the opposite, shade.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 太陽たいようの光ひかりが射さすこと。日射ひざし。