Because each penis is different, the only way to find out is to measure your penis in both hot and cold states.
Think logically. When something is cold, it constricts and appears smaller – and that includes the penis. Just ask anyone who rushes to cover themselves in a towel after a dip in a chilly pool.
When something is hot, it swells and expands. Just as your feet get a little swollen and take up more space when it’s hot, the penis will puff up a tad, too.
It makes sense, right?
What might happen, though, is that you’re more likely to reach that maximum size in the summer months.
In ideal conditions, in a warm environment, and with appropriate stimulation, assuming arterial factors are in order (no diabetes, or old age, or nerve damage), warm weather will help you achieve maximum filling, urologist Dudley Danoff told MEL Magazine.
It’s more likely to be filled to the max in the summertime than wintertime.
But as we mentioned, it’s pretty unlikely that your erections have been so significantly below the full capacity of your penis that it would dramatically increase with the heat – we’re not talking an additional few inches, but just a very slight swelling.
A change in flaccid size may be more noticeable, but you'd have to check your penis on a regular basis to be aware of normal fluctuations throughout the day.
In theory, hot weather could make your penis a little bigger, but you'd have to look very closely to notice.
A massive penis is not required for sexual pleasure for you or your partner, and a few millimeters extra in girth or length is unlikely to have any effect on your sexual performance.