Question

January 31st was on a Tuesday; it was the 27th consecutive day in which it did not rain. What day of the week was it when it last rained? 

Answer 1

It did not rain in that week.It rained on 31-27=4th of January(ON A Wednesday) last,almost 4 weeks ago but in the same month. 
Check if 
Your question's last line
is correct or not,I think the
word "week" should be replaced
by month.

Answer 2

Answer:

3rd day of the week and Wednesday    

Step-by-step explanation:

Given that January 31st was Tuesday and it was the 27th consecutive day in which it did not rain

Here we need to find on which day of the week it was rained

The day on which day it was rained = 31st day - 27 days = 4th day

Therefore, here we can say that on 4th January it was last rained

And it was exactly 3 weeks and 6 days ago (27 days ago)

As we if 31st day is Tuesday, 3 weeks ago its will be Tues day

⇒ from Tues day 6 days ago it will be Wednesday.