How we know: Sources are listed at the end. Weather figures are official climate normals; route and seasonality facts come from the cited travel and airline references. Wildly does not publish fare averages in prose; live prices are on the linked route pages.
Greece has two distinct trips inside one country. The island trip (Cyclades, Dodecanese, Ionian) has a hard season, roughly late April to late October, when ferries run full schedules and island hotels are open. The mainland trip (Athens, Delphi, Meteora, the Peloponnese, Thessaloniki) works year-round and is at its most comfortable in spring and autumn. For most first-time visitors, late May to mid-June and September to early October are the sweet spot: warm sea, everything open, and less heat and crowding than July and August.
Athens weather by month
Official 1991–2020 climate normals for downtown Athens, from the National Observatory of Athens:
| Month | Avg high | Avg low | Rain | |---|---|---|---| | January | 56°F (13°C) | 45°F (7°C) | 2.2 in | | February | 58°F (14°C) | 45°F (7°C) | 1.7 in | | March | 63°F (17°C) | 49°F (9°C) | 1.8 in | | April | 70°F (21°C) | 54°F (12°C) | 1.1 in | | May | 80°F (27°C) | 63°F (17°C) | 0.8 in | | June | 89°F (32°C) | 71°F (22°C) | 0.5 in | | July | 94°F (34°C) | 76°F (24°C) | 0.4 in | | August | 94°F (34°C) | 76°F (24°C) | 0.2 in | | September | 85°F (30°C) | 69°F (20°C) | 1.0 in | | October | 76°F (24°C) | 61°F (16°C) | 1.5 in | | November | 66°F (19°C) | 54°F (12°C) | 2.8 in | | December | 58°F (14°C) | 48°F (9°C) | 3.0 in |
The pattern is classic Mediterranean: almost no rain from May to September, average highs in the mid-90s in July and August, and a mild, wetter winter with highs in the high 50s. The islands are a few degrees cooler in summer thanks to the wind.
Season by season
November–March (winter). Athens is mild and quiet, and the mainland archaeological sites are nearly empty. Island travel is impractical: Wikivoyage notes that in the January–March off-season Aegean weather can be extremely rough and boats are often kept in port for days, and many island hotels close. Crete and Rhodes keep some services running.
April–May (spring). Wildflowers, comfortable highs from the low 70s to around 80°F, and islands reopening through April. Greek Orthodox Easter (the date differs from Western Easter most years) is the biggest domestic holiday, with Greeks travelling home; book around it. The sea is swimmable by late May.
June–August (summer). Hot, dry and busy. The heat peaks from mid-July to mid-August, when the midday sun is intense and locals avoid exertion in the early afternoon (Wikivoyage); the northerly meltemi winds take the edge off on the islands. Ferries and island hotels fill in August around the 15 August national holiday. This is the season for the Cyclades party islands and for anyone tied to school holidays.
September–October (autumn). The sea is at its warmest in September, crowds thin after mid-month, and October is still warm enough for swimming on Crete and in the south. Island services begin winding down through October and most Cycladic hotels are closed by early November.
Getting there from the US
Athens (ATH) is the only Greek airport with nonstop US service. American Airlines, Delta and United operate seasonal flights from North America to Athens, generally April to October (Wikivoyage). Outside that window, and for Thessaloniki or the islands at any time, you connect through a European hub such as Paris, Frankfurt, Amsterdam, Rome or London, or via Istanbul or the Gulf.
For today's prices see JFK to Athens, Newark to Athens, Chicago to Athens and LAX to Athens, or compare every US origin on the flights to Athens hub.
When fares tend to be lowest
US–Greece is one of the most seasonal transatlantic markets: nonstop capacity exists only in summer, and that is also when demand peaks, so July and August fares are usually the year's highest. Fares are typically lowest from January through early March and again in November, when every itinerary connects and demand is at its lowest. Late April to May and late September to October are the compromise: shoulder-season fares with island season still running.
Set a price alert for your dates rather than guessing. Wildly checks prices daily on the routes you track and emails you when the fare drops to your target; the route pages above show recent prices so you can set a realistic one.
Entry requirements for US citizens
Greece is in the Schengen Area. US passport holders do not need a visa for tourism and may stay up to 90 days in any 180-day period across the Schengen Area as a whole (Wikivoyage, "Travelling around the Schengen Area"). Carry a passport valid for at least three months beyond your planned departure.
The EU's ETIAS pre-travel authorisation has not launched. As of 17 September 2026, Fragomen reports that the EU has no proposed start date on its official ETIAS site and will announce one several months ahead. Check the official EU page before you fly.
Where to go, by season
- November–March: Athens, Thessaloniki, Delphi, Meteora, Nafplio and the Peloponnese; Crete's cities stay lively.
- April–May: Add Crete, Rhodes and the Peloponnese coast; the Cyclades open but are not at full service until May.
- June–August: Any island, with the trade-offs above; the larger Dodecanese islands absorb crowds better than Santorini and Mykonos.
- September–October: Islands first while the water is warmest, then mainland and Crete as island hotels close.
FAQ
What is the best month to visit the Greek islands? June and September: warm sea, full ferry schedules, and less heat and crowding than July–August.
Can you visit Greece in winter? Yes, for Athens and the mainland. Highs are in the high 50s and archaeological sites are quiet. Skip the islands; ferries are weather-dependent and many hotels close.
Are there nonstop flights from the US in winter? Not usually. US nonstops to Athens are seasonal, roughly April to October (Wikivoyage), so winter trips connect through a European or Gulf hub.
How hot does Athens get? Average July and August highs are about 94°F (34°C), and heatwaves push well above that. Plan outdoor sightseeing for early morning and evening.