Concept of Rain in Islam

In Islam, why Rain is considered a mercy from God? There are many Hadith/Ayahs where this is explained: > And We send down from the sky rain chartered with blessing, and We > produce therewith gardens and grain for harvests. {**Quran 50:9**} > > It is Allah who sends the winds, and they stir the clouds and spread > them in the sky however He wills, and He makes them fragments so you > see the rain emerge from within them. And when He causes it to fall > upon whom He wills of His servants, immediately they rejoice **{Quran 30:48}** > > O Allah! Let it be a strong fruitful rain. **{Bukhari 1032}** > > The people came to the Prophet weeping (due to drought). He said > (making supplication): O Allah! give us rain which will replenish us, > abundant, fertilising and profitable, not injurious, granting it now > without delay. He (the narrator) said: Thereupon the sky became > overcast. **{Abu Dawud 1169}** > > We are given rain by Allah’s mercy, Allah’s providence, and Allah’s > grace. **{Bukhari}** and so on Question: -------- Why "Rain" is considered a mercy from God in Islam, why there are Duas/Ayahs/Hadiths for getting "rain" ?? Remember, places where it is always raining, people will consider a sunny day as a huge blessing, so why there are no Duas/Hadith/Ayahs for sunshine? As Islam began in a desert in 7th century, they had no clue that there are places on earth where it is always raining (like England)... If they knew, they wouldn't have taken rain as a blessing from God... Just like they didn't take 'Sunshine' as a blessing from God as there are no Ayahs/Hadith/Duaa where a supplication for "sunshine" is being depicted ???? Thanks.