Where Is It Warm in Europe in May? Islands Ranked by Sea Temperature

In May the sea is warmest around Gran Canaria (22 °C), El Hierro (21 °C) and Tenerife (21 °C). Average daytime highs across the 32 islands below range from 20 °C to 27 °C; the warmest days are on Cyprus (27 °C). None of them has real beach weather this month (sea and air both at 22 °C or more) — it is a month for walking, towns and quiet beaches rather than swimming. Hiking conditions (15–25 °C by day, little rain) are best on Gran Canaria, El Hierro, Tenerife, La Gomera, La Palma, Lanzarote and others. Driest: Lanzarote with about 1 rain days.

Sources: ERA5 reanalysis via Open-Meteo (air temperature, rain; 10-year average) and Open-Meteo Marine API (sea surface temperature; 3-year average). Data by Open-Meteo.com (CC BY 4.0). Area averages — individual years vary.