Looking on the internet deeply has found these results:

In a rainy day is the most popular phrase on the web.

Ona a rainy day 10 results on the web	In a rainy day 126,100 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	The followings sentences are always confuse me. Hopefully someone could help me.Thank you. Children are not allowed to go out in a rainy day. Children are�... Save money in a rainy day fund for life's unexpected emergencies. We have insurance for almost every aspect of our life: car, home, life, travelers, etc. Watercolor Painting in a Rainy Day 2 (Hangul: ??? ? ??? 2; RR: Bioneun nal suchaehwa 2) is a 1993 South Korean film, the sequel of Watercolor Painting �... Watercolor Painting in a Rainy Day (Hangul: ??? ? ???; RR: Bioneun nalui suchaehwa, English title according to Cine21 is A Sketch of a Rainy Day) is�...

Ona a rainy day

10 results on the web

In a rainy day

126,100 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

The followings sentences are always confuse me. Hopefully someone could help me.Thank you. Children are not allowed to go out in a rainy day. Children are�...
Save money in a rainy day fund for life's unexpected emergencies. We have insurance for almost every aspect of our life: car, home, life, travelers, etc.
Watercolor Painting in a Rainy Day 2 (Hangul: ??? ? ??? 2; RR: Bioneun nal suchaehwa 2) is a 1993 South Korean film, the sequel of Watercolor Painting �...
Watercolor Painting in a Rainy Day (Hangul: ??? ? ???; RR: Bioneun nalui suchaehwa, English title according to Cine21 is A Sketch of a Rainy Day) is�...