“三伏天” 为什么叫 dog days？

Sanfu, also called China's "dog days of summer", refers to three 10-day periods that are predicted to have the hottest days of the year. 

the period between early July and early September when the hot sultry weather of summer usually occurs in the northern hemisphere

sultry [ˈsʌltri]：闷热潮湿的

hemisphere [ˈhemɪsfɪr]：半球

The “dog days,” I always thought, were those summer days so devastatingly hot that even dogs would lie around on the asphalt, panting.

devastatingly [ˈdevəsteɪtɪŋli] ：破坏性地

asphalt [ˈæsfɔːlt]：沥青；柏油

pant：气喘，喘息

The ancient Greeks thought of the constellation Canis Major as a dog chasing Lepus, the hare. The star Sirius is the dog’s nose; the Greeks called it the “dog star”.

To the Greeks and Romans, the “dog days” occurred around the day when Sirius appeared to rise just before the sun, in late July. They referred to these days as the hottest time of the year, a period that could bring fever, or even catastrophe.

Although July and August are generally known as the hottest months of the year in the Northern Hemisphere, the hottest period can vary from year to year. And depending on your latitude, the astronomical dog days can come at different times.

虽然7月和8月一般被称为北半球一年中最热的月份，但每年最热的时期都会有所不同。且根据纬度的不同，天文学上的“三伏天”也会在不同的时间到来。