Some have postulated men mocked Noah about a coming flood because they had never seen rain. Others have pointed to the rainbow covenant in Genesis 9 as a suggestion that rain was a new phenomenon, else rainbows would have been seen previously. The existence of rain suggests the existence of rainbows.
God spoke to the Flood survivors saying,
This is the sign of the covenant that I make between me and you and every living creature that is with you, for all future generations: I have set my bow in the cloud, and it shall be a sign of the covenant between me and the earth. When I bring clouds over the earth and the bow is seen in the clouds, I will remember my covenant that is between me and you and every living creature of all flesh. And the waters shall never again become a flood to destroy all flesh. When the bow is in the clouds, I will see it and remember the everlasting covenant between God and every living creature of all flesh that is on the earth.But the promise of the rainbow does not mean that rainbows had not been seen previously. The rainbow is the sign of the covenant. As other commentators have noted, bread represents Christ in the Eucharist, yet bread pre-dated this. Jesus gave new meaning to the bread in this context. It is possible that God gave meaning to the rainbow.
Nevertheless there is at least some suggestion that the rainbow was new.
In Genesis 2 it informs us that the ground was watered by a mist or spring.
When no bush of the field was yet in the land and no small plant of the field had yet sprung up—for the LORD God had not caused it to rain on the land, and there was no man to work the ground, and a mist [or spring] was going up from the land and was watering the whole face of the ground—Prior to the Fall there was no rain, the hydrologic cycle was much gentler than the system we encounter today. The rain may have started after the creation of man, though I can think of no reason for this begin. A better case could be made for after the Fall given the cosmological consequences of Adam's sin. Much changed at that time when we see the introduction of death into the world. Are there were mountains pre-Flood though likely of lesser size than the post-Flood ranges that we observe.
And the waters prevailed so mightily on the earth that all the high mountains under the whole heaven were covered. The waters prevailed above the mountains, covering them fifteen cubits deep. (Gen 7)If the highest mountains were covered by nearly 7 m of water they would not have been as high as they are now. There is plenty of water to cover a uniform earth to a significant depth, just not 8,000 m.
Mountains have an effect on the weather and their presence is one of the causes of rain.
If the world was essentially 1 continent before a peri-Flood break up then the movement of the ocean currents and the consequences of such would have been different in the antediluvian world.
And God said, "Let the waters under the heavens be gathered together into one place, and let the dry land appear." And it was so. God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good. (Gen 1)If the waters are predominantly in one place—the seas, then the land would likely be in one place. Of course some of the water was over the land in forms of streams, rivers, mists and springs.
There is also the suggestion that even seasons are a post flood phenomenon, they are first mentioned following the Flood. While creating God said,
Let there be lights in the expanse of the heavens to separate the day from the night. And let them be for signs and for seasons, and for days and years, and let them be lights in the expanse of the heavens to give light upon the earth. (Gen 1)While this is a reasonable translation and is one followed by most versions, the word translated season is mow`ed, and it could be argued that the translators are reading their post-Flood assumptions into the translation. Mow`ed occurs 223 times in the Bible and is seldom translated season: 13 times in the KJV, once in the NET. The meaning appears to be related to appointment, whether that be time or place. So in Genesis the sense would be appointed times; seasons if they existed, but possibly months or years, or the general sense of maintaining a calendar for whatever reason (eg. festivals). The word usually used for season is the word for time (`eth). That it is not used here suggests an emphasis on appointed times. It seems a reasonable translation is:
Let there be lights in the expanse of the heavens to separate the day from the night. And let them be for signs for (appointed) times, and for days and for years,...The first mention of seasons explicitly is immediately following the Flood. After Noah offers a sacrifice God says,
While the earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease. (Gen 8)It is very possible that it rained before the Flood. That rain occurred at the time of the Flood and the mention of the rainbow as a sign certainly does not preclude it. However other passages suggest that the pre-Fall and very possibly the pre-Flood climate did not experience the current hydrologic cycle of rain (and snow). Pre-Flood we have:
- Ground watered by mist or spring
- A single continent of land
- A landscape with hills or small mountains
- No mention of specific seasons