The climate in Greece can be amazingly good for you!
Greece has a classic Mediterranean climate, enjoying mild, wet winters and hot, dry summers that are sometimes scorching conflagrations. This similar climate affects all the usual coastal locations, including those of the Athens environs, the Cyclades, the Dodecanese, Crete, the Peloponnese and parts of the Sterea Ellada (Central Continental Grece) region, the Sporades and all other Greek island groups and landmass.
The climactic Pindus mountain range has a dynamic affect on the climate of the whole country, with areas to the west of the range considerably damper on average (due to direct exposure to south-westerly weather systems bringing rain and mists) – greater than the areas lying to the east of the range (called the rain shadow effect).
The high areas of Northwestern Greece (parts of Epirus, Central Greece, Thessaly, Western Macedonia) as well as in the steep central parts of the Peloponnese mountain areas, including parts of the prefectures of Achaia, Arcadia and Laconia enjoy an Alpine climate with snowfalls and even skiing resorts.
However, the inland parts of northern Greece, in Central Macedonia and East Macedonia and Thrace feature a temperate climate with cold, damp winters and hot, dry summers with frequent thunderstorms. Although snow may fall in these areas, it is rare, yet not impossible, to experience snowfall in Athens and other warmer areas.
Finally, the Meltimi from the north brings a kind of welcome natural air conditioning, often in strong gusts and prolonged battering gales. The sea at this time looks like a mass of stampeding white horses, and even a stone topped table can be upturned - I kid you not. Hold on to your hats and sunglasses - those mythical zephyrs are only too keen to wrench them off and send them flying away! However, mostly this refreshing wind is a godsend - quite literally for ancient Greeks as they truly believed it was a gift from Zeus.
The southern side of Rhodes and Crete escapes the Meltimi but is subject to the often hot and dry Sirocco wind that blows up from Africa. In August it can seem painfully hot, although it often has less moisture and for some is pleasantly welcome.
It would be ludicrous to harp on about how wonderfully sunny Rhodes is because it's a basic truism - just as snow in Antarctica is a truism too obvious to mention. Take a look at the climate graph below.
Rhodes is hot and the original sunshine isle: a sun worshippers paradise and a place where recharging your empty batteries via copious sunlight and gorgeous sunsets is as easy as sipping a favourite cocktail at sundown.
Note the topography↓ and also note that the southern stretch of Rhodes that is virtually not that far from Egypt, and especially Lindos, can get roasting hot during July and August - so be warned. This side of Rhodes is subject to the hot Sirocco wind that blows up from Africa - so there is no hint of the Northern Meltimi wind here. The refreshing Meltimi, that originates in the Balkans, lends a cooling effect to the North coast - even though it can also be baking hot in July and August.
Air conditioning during the high season on Rhodes is a real must - so if you are doing it on the cheap, still make quite sure your room has the means to cool you down when the temperature hits 40c plus. In fact get the hotel, or whoever, to put it in writing and take the proof with you. Often there is an extra charge payable locally, although 4 star plus places usually include it as standard in the price you pay.
Clothing needs to be light cottons and linens (man-made material can feel sticky and silk gets stained with perspiration - that whitish tide-mark). But do bring something warm for those windy evenings when the temperature can seem a bit chilly.
The other prerequisites are a natural insect repellent and the determination to drink plenty of bottled water. The quickest way to get heat stroke is to fail to drink plenty of water and/or consume too much alcohol. Keep cool and drink copiously, especially when the thermometer hits 40c - I was in Santorini once when it hit 46c. I survived that record-breaking high but a few locals did not. Be careful.