Generally, Dubrovnik is slightly warmer than Split, though the difference is often marginal due to their shared Mediterranean climate along the Adriatic coast. Because Dubrovnik is located further south, it tends to see slightly higher average temperatures in the winter months and transitions into spring a few days earlier. In the peak of summer (July and August), both cities experience average highs around 30°C (86°F), but Dubrovnik’s southern position and specific topography can sometimes lead to higher nighttime "lows," making for balmier evenings. However, Split can occasionally feel hotter during the day due to urban heat island effects in its more densely built-in areas. When comparing sea temperatures, both are remarkably similar, peaking at around 25°C (77°F) in August. Ultimately, while Dubrovnik technically holds the "warmer" title by a fraction of a degree on average, your experience in either city will be dominated by plenty of sunshine and heat from June through September.