They know its rainy season because of low pressure during rain storms. Although many folks dont cool their animals it naturally gets colder in most homes during winter months. Meaning daytime highs and night time lows will naturally vary in any home enough to trigger breeding and or fasting.
Gregg Graziani said when they had the drought in Florida a couple of years ago and they had no rain he had about 100 females that should have laid and didnt because the lack of low pressure from no rain storms. He said he was able to control everything else like temps and humidity but not air pressure.