Background: Previous research has found that unusually hot temperatures reduce birth rates eight to ten months later.

Objective: We examine one of the potential mechanisms behind this relationship: the connection between ambient temperature and sexual activity.

Methods: We use individual-level data provided by three waves of the Hungarian Time Use Survey between 1986 and 2010 and daily weather data from the European Climate Assessment & Dataset project.

Results: Hot temperatures do not have a significant effect on sexual activity on a given day. Studying the dynamics of the relationship, we found that temperature does not influence sexual activity on subsequent days either.

Conclusions: Since high temperatures seem to have no negative effect on sexual activity, the relationship between temperature and sexual activity might be a mechanism of minor importance in the relationship between temperature and birth rates.

Contribution: Our paper is the first study of the relationship between ambient temperature and sexual activity that uses time use data.