climate, seasons, ecology & geology

Climate & Seasons

Hydra has the full cycle of seasons, with hot, dry summers, chilly, wet, windy winters, and a temperate spring and fall.

Spring (end of March/early April and May)
Temperatures range between 15 and 25 degrees Celsius. This period can still see a lot of rain. Everything is green and the wild flowers festoon the hills and paths with bright reds, yellow, and purples. Sea temperatures start to rise and some die-hards start their swimming season.

Summer (June through August)
The weather on Hydra gets hotter as the summer progresses. Temperatures tend to hover in the low to mid 30s can reach into the 40s for stretches. Hot winds blowing up from Africa, especially in August, can offer a bit of relief. Sea temperatures range between 20 and 25 degrees across the summer.

Fall (September into November)
This is, for many, the best time of year on Hydra. Temperatures are still warm, though evenings can get chilly. The sea is still warm enough for swimming, and the weather is perfect for hiking and exploring the island.

Winter (November into March)
The winter months are generally quite chilly, rainy, and windy, dotted with the occasional sunny, warm day. Temperatures tend to hover between 10 and 15 degrees.

From the World Climate Guide. See

Geology & Ecology

Itself basically a 52 km2 rock, the vast part of which is uninhabited, Hydra is characterized by rocky mountains and hillsides, pine-forested valleys, and 56 km of craggy coastline. The highest peak is Mount Eros, which occupies the central zone and raises to an altitude of 500m. The Zogeri range of mountain lies to the south of Hydra and the Ombari range to the north. Hydra’s population of nearly 2,000 is predominately concentrated along about 3 km of coastline on the northern side of the island in Hydra Town and the neighboring villages of Kamini, Vlychos, and Mandraki.

In ancient times Hydra was covered with pines and had plenty of water (the source of the island’s name). Today, the island is mostly dry, its water supplied by a desalination plant behind Mandraki Beach Resort. Hydra still has a working well in the area of Kala Pigadia (meaning “good wells”), and some residents will take plastic bottles down to fill up with free drinking water.

The wells of Kala Pigadia

By the time temperatures start soaring in mid-summer, most ground-level vegetation (grasses, flowering plants, scrub brush) has dried out and turned brown, but colorful spring and early summer bring a wealth of wildflowers, including white and yellow daisies, cyclamen, irises, thistles, and red poppies.  Purple, orange, and even yellow bougainvillea, hibiscus, plumbago, and geraniums bloom and persist throughout the summer. Century plants, prickly pears, Hottentot figs, and cacti are ubiquitous. In addition to the pine trees in the hills, cypress, olive, eucalyptus, fig, lemon, and even orange trees abound.


Birds species include partridges, quails, swallows, owls, and many migratory birds; small, harmless bats are common in the evenings. Animal species include rabbits and foxes (generally up in the mountains), as well as equines (horses, mules, donkeys), feral and domestic cats, and domestic dogs, as well as livestock such as sheep, goats, chickens, and roosters. Tortoises are common. Semipoisonous (nonlethal) snakes exist in more rural areas and are rarely seen in town.


Sadly, dynamite and small-net fishing decimated the fish population in the waters around Hydra. Due to EU regulations banning dynamiting and specifying minimum net sizes, the marine ecology is regenerating. Marine life consists a variety of smaller fish, sometimes quite colorful, swimming singly or in schools (e.g., silvery-blue, needlelike gar fish, small tuna, barbounia, mullet, red snapper, small barracuda, dolphins, the odd swordfish), the rare sea turtle), as well as sea urchins, octopuses, star fish, squid, sea turtles (very rare), eels, and sea centipedes (which feed on the sea floor but should not be approached). In some summers jellyfish float through the local waters for a few days, but for the most part the seas around Hydra are free of them.