We investigated the association of the variability of acute myocardial infarction (AMI) occurrences between warm and colder periods and the conventional cardiovascular risk-factors. For the registered 429 first-ever-AMI event, the odd of suffering an AMI during the colder period was significantly higher (OR 1.47, 95%CI: 1.21–1.78). None of the conventional cardiovascular risk factors explains the excess risk of AMI during the colder period pointing towards the influence of AMI triggering factors in the time preceding onset of AMI irrespective of presence or absence of cardiovascular risk-factors.