Sea Temperature in Rab Island in May (2026) – Swimming Guide
Sea temperature in Rab Island in May averages 18.3°C (typical range 15.9°C–20.7°C). Swimming conditions, 10-day trends, and top beaches.
Typical Range: 15.9°C – 20.7°C
Standard swimwear is fine for quick dips. For toddlers and sensitive swimmers, a thin 2mm shorty wetsuit is recommended.
Povoljni termički uvjeti za cjelodnevni boravak uz more
7 rainy days · UV Index 7
Sea Temperature Progression in May by Decade
Multi-year oceanographic measurements across early, mid, and late month:
Annual Oceanographic Climatology for Rab Island
Multi-year historical records by the Croatian Meteorological and Hydrological Service (DHMZ) & Institute of Oceanography and Fisheries (IZOR)
| Month | Sea Temperature | Day Air | Night Air | Sun Hours | Rain Days | Swimming Verdict |
|---|---|---|---|---|---|---|
| January | 11.9°C (10.1° – 13.5°) | 10.2°C | 4.1°C | 4.2 h | 7 d | Crisp & cool |
| February | 11.2°C (9.5° – 12.7°) | 11.1°C | 4.5°C | 5.1 h | 6 d | Crisp & cool |
| March | 12.5°C (10.9° – 14.2°) | 14.2°C | 7.2°C | 6.4 h | 7 d | Crisp & cool |
| April | 14.9°C (13.2° – 17.2°) | 18.1°C | 10.5°C | 7.8 h | 8 d | Crisp & cool |
| May → | 18.3°C (15.9° – 20.7°) | 22.8°C | 14.8°C | 9.2 h | 7 d | Refreshing & invigorating |
| June → | 22.5°C (19.5° – 25.1°) | 26.9°C | 18.6°C | 10.5 h | 6 d | Comfortable & warm |
| July → | 25.1°C (22.9° – 27.5°) | 29.8°C | 21.2°C | 11.8 h | 4 d | Very warm & ideal |
| August → | 26.1°C (24.1° – 28.5°) | 29.6°C | 21°C | 11 h | 4 d | Very warm & ideal |
| September → | 23.4°C (21.1° – 25.5°) | 24.8°C | 17.1°C | 8.6 h | 6 d | Comfortable & warm |
| October → | 19.7°C (17.5° – 22.1°) | 19.6°C | 13°C | 6.2 h | 8 d | Refreshing & invigorating |
| November | 16.2°C (14.3° – 17.9°) | 14.9°C | 8.8°C | 4.5 h | 9 d | Crisp & cool |
| December | 13.5°C (11.7° – 14.9°) | 11°C | 5.2°C | 3.8 h | 8 d | Crisp & cool |
Top Rated Beaches in Rab Island for this Season
Curated bathing spots featuring verified water cleanliness and supreme swimming comfort (38 verified locations):
Expert Swimming & Marine Tips
🌬️ Winds & Marine Currents
Summer afternoons regularly welcome the refreshing Maestral (NW) sea breeze. A strong Bura (NE) wind can temporarily drop surface water temperatures by 1–2°C, especially in shallow coastal coves.
☀️ Sun Protection & UV Exposure
In peak summer months, the UV index regularly surpasses 8. Limit unprotected sunbathing between 11:00 AM and 4:00 PM, and always use high-factor water-resistant sunscreen.
🤿 Water Clarity & Sea Urchins
The Adriatic Sea here consistently scores excellent water quality under EU bathing water directives. Sea urchins on rocky shallows serve as nature’s bio-indicator of immaculate water purity.
Frequently Asked Questions – Sea Temperature in Rab Island
Is it warm enough to swim in Rab Island in May?
In May, average sea temperature in Rab Island is 18.3°C. Refreshing & invigorating / Best for active swimming. Standard swimwear is fine for quick dips. For toddlers and sensitive swimmers, a thin 2mm shorty wetsuit is recommended.
What is the air temperature and daily sunshine in May?
Average daytime air temperature reaches 22.8°C (14.8°C at night), featuring approximately 9.2 hours of bright sunshine daily and only 7 rainy days.
How does sea temperature evolve from early to late May?
During early May (1st–10th) water averages 17.5°C, mid-month (11th–20th) sits at 18.3°C, and late month (21st–31st) reaches 19.1°C.