干打雷，不下雨
gān​dǎ​léi​bù​xià​yǔ

all thunder and no rain

  1. 干 乾 gān adverb
    for nothing
    in vain; with no result; only; simply; helplessly
  2. 打雷 dǎ​léi verb + noun
    to thunder
    to rumble with thunder; to have a clap of thunder
  3. ， bù
    non-Chinese
  4. 不 bù adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  5. 下雨 xià​yǔ verb + noun
    to rain
    to rain; for rain to fall from the sky