More on winds to expect in May and June in Croatia - 8 April 2023

This post presents the most prevailing winds in May and June in the Adriatic sea, based on the data from 2018 to 2022 in Dubrovnik. These data are taken from the website of the University of Iowa Environmental Mesonet (IEM). The image below shows the wind rose for an average full day from May and June 2028 to 2023. The size of the bars represents the frequency of winds from each direction, expressed in %. The colour indicates the expected wind strength.. 

Overall, the winds will be mainly from east, north-north-east and west-north-west directions. Let's have a look at the time of day, when to expect them and what this means for our sailing...

The 8 pictures below show the average wind rose in May and June in 3 hour periods for a full 24 hour period. Let's look at the different winds and their times.

The Night winds, 21:00 to 9:00, are almost exclusively of Tramontana and Levant. They correspond to the land breeze or katabatic winds created by a difference in pressure between the sea, which remains warm at night, and the surrounding mountainous coastal areas, which become much colder after sunset. It is important to take this into account when choosing an anchorage at night, so as not to be surprised when the wind starts blowing at around 22:00! Tramontana blows from the NNE more than 20% of the nights (adding the percents). The colour of the NNE bars goes up to brown, which means winds sometimes over 20 m/s (Beaufort 6). The Levant blows from the NE to SE. It is the most prominent wind at this time of the year. It tends to be much milder than the Tramontana (Beaufort 6). 

Morning winds, 9:00 to 12:00, blow almost exclusively from the southern sector and are generally mild, except when blowing from the SE.

Early afternoon winds, 12:00 to 15:00, blow from SE to NW. SE winds tend to increase in strength in the early afternoon, while S and SW winds tend to veer westwards and increase in strength.

In the middle to late afternoon, winds blow almost exclusively from the WNW, before disappearing in the evening.  They correspond to sea breezes caused by the temperature difference between the land heated by the sun and the sea, resulting in anabatic winds blowing from the sea to the land with increasing in strength as the land warms, before disappearing as the sun moves closer to the horizon.

Midnight to 3:00	3:00 to 6:00
6:00 to 9:00	9:00 to 12:00
Noon to 15:00	15:00 to 18:00
18:00 to 21:00	21:00 to 12:00

All in all, the winds seem to be quite predictable in strength and direction during this period and we will take this information into full consideration on our route to Pula.