When the rainstorm came, it began to rain hard and the wind blew strongly.

暴风雨来临时，开始下大雨，刮大风。

youdao

It began to rain hard.

开始下大雨了。

youdao

It began to rain hard.

的翻译是：它就开始下雨。

youdao

"The strength of the crowd seemed strongest in the hard rain on Sunday afternoon.

VOA: special.2009.08.10

But we do not want it to rain too hard.

VOA: special.2010.05.30

"It started to rain really hard in the evening, and began to flood, " said Augustina Garcia Orsi, a 25-year-old student.

NPR: Argentina: Flooding From Torrential Rains Kill 52

There were 50 to 60mph gale force winds, the rain was hard.

BBC: Snowdon 4x4 case: Craig Williams jailed for 22 months

Tell them to 'batten down the hatches', because there's a HARD RAIN coming.

FORBES