Summer is the Best Time for Sperm, Scientists Indicate 0 10

A new study has shown that the best sperm quality is observed in the summer, while the lowest is seen in the winter. Researchers from the UK, Canada, and Denmark studied sperm samples from 15,581 men aged 18 to 45 from Denmark and Florida.

The analysis demonstrated that sperm motility – that is, their ability to move actively and efficiently – consistently peaked in June and July in both regions. Identifying such seasonal fluctuations may assist in the field of reproductive medicine: by adjusting the timing of examinations and procedures, specialists can provide more accurate recommendations to couples planning conception.

The study, published in the journal Reproductive Biology and Endocrinology, showed that sperm motility exhibits similar seasonal changes across different climate zones and is influenced more by the time of year than by weather conditions. The lowest temperatures were recorded in December and January – even in Florida, where a warm climate generally prevails throughout the year.

At the same time, the researchers found no seasonal differences in either the overall sperm concentration (that is, their quantity in the semen) or the volume of ejaculate – the amount of seminal fluid released during ejaculation. In other words, the season affects the ability of sperm to move actively but does not reflect on their quantity.

The authors of the study suggest that such seasonal changes may have a more significant impact on male fertility than simple temperature fluctuations. Normally, the temperature of the testicles, where sperm are formed and stored, should be about 2-4 degrees lower than the average body temperature, which is around 37 °C. Deviations in either direction – whether an increase or decrease – can impair sperm motility and, consequently, reduce a man's reproductive capacity.