Looking on the internet deeply has found these results:

It has been raining all week. is the most popular phrase on the web.

It has rained all week. 130,400 results on the web	It has been raining all week. 1153,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Although it has rained shrimp once or twice. (camera shutter clicks) It hasn't rained in weeks. You noticed how it has rained but its still hot? Dear Aunt Lucy. I have arrived in London and so far it has rained, poured, drizzled and chucked it down. Nobody has mentioned my birthday all week. It has rained 1.65 inches of rain today. It has rained 1.65 inches of rain today. It has rained 1.65 inches of rain today.	She came in last week and... it had been raining and she was completely soaked. First time you came to visit me in Brazil... It didn't stop raining for a week. It's been raining all day here. It is interesting that the British Minister of Agriculture, Mrs Beckett, has said that she will decide when farmers can go into the field, or when it is too wet or has been raining. As far back as I can remember, it has been raining Nobody has mentioned my birthday all week. As far back as I can remember, it has been raining

It has rained all week.

130,400 results on the web

It has been raining all week.

1153,000 results on the web

More popular!

Although it has rained shrimp once or twice.
(camera shutter clicks) It hasn't rained in weeks.
You noticed how it has rained but its still hot?
Dear Aunt Lucy. I have arrived in London and so far it has rained, poured, drizzled and chucked it down.
Nobody has mentioned my birthday all week.
It has rained 1.65 inches of rain today.
It has rained 1.65 inches of rain today.
It has rained 1.65 inches of rain today.

She came in last week and... it had been raining and she was completely soaked.
First time you came to visit me in Brazil... It didn't stop raining for a week.
It's been raining all day here.
It is interesting that the British Minister of Agriculture, Mrs Beckett, has said that she will decide when farmers can go into the field, or when it is too wet or has been raining.
As far back as I can remember, it has been raining
Nobody has mentioned my birthday all week.
As far back as I can remember, it has been raining