It has been established that the climate and the season have tremendous effects on various aspects of human and animal life. This has been understood since the times of Hippocrates and Aristotle. Hippocrates once said that a full and complete study of medicine must take into consideration the season and the effect of the season’s climate. Current research has shown that the physical aspects of the human body changes with the seasons and the weather. The optimal condition for a functioning body is said to be 64 degrees Fahrenheit (18 degrees Celsius). Now though, there are also studies suggesting the effects of climate on human conception.
For animals, we know that breeding season is dependent upon the climate. Some animal species mate during a particular time of the year to ensure the breed’s continued existence and some do not mate at all if the conditions are not stable. For example, flamingos decline to mate if there is a lack of food resources and a drought. Another example of how animals are affected by the climate comes from the monkey; the Macacus monkey to be exact. This species has been observed to be almost completely sterile during June, July and August in the Northern Hemisphere and November, December, and January, in the Southern Hemisphere.
There have been some studies that examine the climate’s effect on human conception as well. A study conducted by Engle and Shelesnyak in 1934 reported that there was a higher frequency of menstrual disturbances in young and adult woman during the summer months. Other surveys report that there are more miscarriages during the warmer summer months.
Hong Kong is a good place to conduct research into this topic because it has a large population of more than 3 million living in a relatively small area of square mileage. The four seasons are also distinct in this area. The study used a ten-year record of births and monthly weather records. The results showed that the monthly conception rate in Hong Kong was negatively correlated with the temperature, meaning more children were conceived during months with lower temperatures.
The correlation between the temperature and conception was 0.96 in urban areas and 0.93 in rural areas, showing little difference between the two areas distinct areas. While the numbers varied, the most children, 9,103, were conceived during the winter months, December to February, in Hong Kong. The summer rates of conception were generally about 30 percent lower than those winter rates. What does this mean for those of you trying to conceive? It could mean that you’ll have more luck in cooler climates.
Source: Climate and Conception Rates in Hong Kong. Human Biology. Wayne State University Press. Vol. 35, No. 3 (September, 1963), pp. 366-376.