Cordoba is a southern Spanish city and therefore will be very warm most of the time. Its Mediterranean climate (bordering on African) means that it has exceptionally hot summers with mild and windy winters. It does not rain often, primarily any major rainfall occurs between October and December.
The average summer temperature is 28 °C whilst the average winter temperature is 9.3 °C.
For the most reasonable weather, visit in late spring or early autumn.
Dress and plan accordingly.