Hello how may I help you? Hi I need some information Sure, what can I help you with? Can you tell me what the biggest cloud of all time was? The tallest, widest, or heaviest? Tallest It was a 50,000 foot cloud in Nevada on November 15, 1950. Nice! What about the widest cloud? That's tricky due to hurricanes being so large, but the largest single cloud was 20 miles across in Japan on October 2, 1975. Wow, thanks for that information! That's all I need to know today. Ok, have a good day!