bucket down

No — say "It is bucketing down.". The verb is intransitive and does not take 'rain' as a direct object.

Definition

phrasal verb. to rain very heavily. You use this when it is raining so hard that it feels like someone is pouring buckets of water from the sky.

phrasal verb. to rain heavily and persistently. This phrasal verb is intransitive and typically occurs with the dummy subject 'it'.

simple

“It is bucketing down outside, so take an umbrella.”

contextual

“We wanted to go for a walk, but it started to bucket down just as we reached the park.”

complex

“The match was eventually abandoned after it began to bucket down, leaving the pitch completely waterlogged and unplayable.”

This phrase is almost always used with 'it' as the subject.

Contrast with 'rain cats and dogs', which is a well-known idiom but much less common in natural modern speech than 'bucket down'.

It is bucketing down the rain.

It is bucketing down.

The verb is intransitive and does not take 'rain' as a direct object.

Particles

down

Separability

inseparable

Pattern

it + bucket + down