It depends on many factors such as your skin type, whether you’ve tanned recently or not, what kind of sunscreen you are wearing, and so on.
But in general, if you have just started tanning, do not expect suntan to develop during or right after being in the sun. Melanogenesis, a process induced mainly by UVB radiation (whereby special cells in our skin called melanocytes produce melanin responsible for skin pigmentation) takes several days, or 72 hours on average.
Immediate darkening of the skin, caused by UVA radiation, may form if you already have enough melanin in your skin such as triggered by recent sun exposure in the preceding days.
A couple of other myths to bust:
- you don’t have to get all red like a lobster in order to get a tan;
- outside temperature has nothing to do with tanning – a hotter day doesn’t translate to better or more effective tanning experience.