Dvanáctka z Jasének is a 12 km race in Hlučín, a town in the Opava District of the Moravian-Silesian Region in Czechia. It is run in September, when local conditions are usually cool for racing, with typical temperatures around 10-19°C.
The race starts in Hlučín, the listed distance is 12 km, and the event has its own website at zavodyzjasenek.wz.cz. September in Hlučín is often mostly cloudy, with average precipitation around 45 mm, so runners should expect mild weather rather than heat.