Summer, specifically July and August, is the busiest time on the Croatian coast and on the islands. This is Croatia's "season," a time when the sun is the hottest, the sea the bluest, and traffic endless. The coast is at its best -- and worst -- during midsummer. Hotel room rates top out; restaurant tables are always full, and crowds can be overwhelming. This is the period that makes or breaks many Croatian businesses that depend on tourism for a year's income, and it can be tough on unsuspecting travelers.
Much of the madness is due to traditional European July and August vacation schedules which coincide with the Croatian coast's glorious summer weather.
Weather in Croatia generally can be divided into two mini-climates. Northern Croatia has a Continental climate, with average temperatures ranging from near freezing in January to about 70°F (21°C) in August. The coastal areas have a more Mediterranean climate, with average temperatures ranging from the mid-40s in January to near 100°F (38°C) in August. Spring and autumn are pleasant and mild along the coast; winter inland can be cold and snowy.
The bottom line is that in July and August, good weather is almost a certainty and tourism is in full swing, but prices and availability on the coast can be prohibitive. Conversely, in the interior, crowds are minimal and prices can reach their lowest levels in summer. Zagreb and other interior cities can be real bargains then because many residents will be on the coast. However, that means many Zagreb restaurants and shops may be closed. A word of warning: The weather on the coast is usually nice, the sea warm, and prices lower in May, June, September, and October, but some establishments, especially those on the islands, might be shuttered and some ferry routes might be canceled or on reduced schedules.
