Santorini Secrets
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Santorini Secrets
The sea temperature in Greece varies significantly by month and region. The water is coolest from January through April (16-17°C), becomes comfortable for swimming in late May and June (20-22°C), and peaks from July through September (24-26°C). The Dodecanese and Crete typically offer the warmest waters, often remaining swimmable deep into October.
For trip planning, treat the Cyclades as a summer-to-early-autumn swim destination: winter seas are usually in the mid-teens Celsius, while late summer and early autumn often reach the low-to-mid 20s Celsius. Use the Greece Sea Temperature Map to compare May, peak summer, and October before choosing beach-heavy islands.
Warmest right now
Rhodes 26.1°C
Strongest current-month average in the selected planning window for July.
Best late-season hold
Rhodes
Early October stays around 25.2°C, making it one of the best options after peak summer.
Comfortable now
9/9
Destinations in the current dataset that are at least 23°C this month.
Source stack: NOAA NCEI, HNODC, HCMR Poseidon System, Copernicus Marine
Reference period: 2014-2023 • Last updated: 2026-02-03
Monthly averages are historical climatology values computed from NOAA OISST V2.1 daily sea-surface temperature data for the 2014-2023 reference period, with regional sanity checks against Greek coastal monitoring summaries. Shoulder-season splits are derived from monthly averages and should be treated as planning guidance.
Temperatures are historical trip-planning averages, not real-time measurements. Authority-confirmed safety restrictions are labeled where available; all other beaches should be verified locally before visiting.
Scan the warmest destinations for the current month, then switch to the heatmap to compare swim windows across the whole year.
Dodecanese
26.1°C in July
Crete
25.1°C in July
Ionian Islands
25.1°C in July
Cyclades
23.8°C in July
| Month | Average °C | Average °F |
|---|---|---|
| July average | 24.1 | 75.4 |
| Jan | 17.1 | 62.8 |
| Feb | 16.6 | 61.9 |
| Mar | 16.7 | 62.1 |
| Apr | 17.4 | 63.3 |
| May | 19.5 | 67.1 |
| Jun | 22.5 | 72.5 |
| Jul | 24.1 | 75.4 |
| Aug | 25.1 | 77.2 |
| Sep | 24.6 | 76.3 |
| Oct | 22.5 | 72.5 |
| Nov | 20.3 | 68.5 |
| Dec | 18.2 | 64.8 |
Use this panel when you want to move from broad comparison into island-level timing: headline temperature, shoulder-season durability, wind penalty, and beach character all matter together.
July average
24.1°C(75 °F)
Swimming Comfort
Comfortable for most swimmers.
Season average (Jun–Sep)
24.1°C
Shoulder season
Early May 18.5°C · Late May 20°C
Early Oct 23°C · Late Oct 21.5°C
Best swim window
June, July, August, September, October
Reference coastline
Perissa Beach
Wind conditions
High winds (Jun, Jul, Aug, Sep). Strong northerly Meltemi winds can make the sea feel cooler and choppier.
This profile makes seasonality obvious: winter minima, late-summer peaks, and whether the destination stays swimmable deep into October.
| Month | Temperature (°C) | Temperature (°F) |
|---|---|---|
| Jan | 17.1°C | 63°F |
| Feb | 16.6°C | 62°F |
| Mar | 16.7°C | 62°F |
| Apr | 17.4°C | 63°F |
| May | 19.5°C | 67°F |
| Jun | 22.5°C | 73°F |
| Jul | 24.1°C | 75°F |
| Aug | 25.1°C | 77°F |
| Sep | 24.6°C | 76°F |
| Oct | 22.5°C | 73°F |
| Nov | 20.3°C | 69°F |
| Dec | 18.2°C | 65°F |
26°C+ Very Warm
Perfect for extended swimming
23-25°C Warm
Comfortable for most swimmers
20-22°C Pleasant
Refreshing, good for active swimming
17-19°C Cool
Bracing, short swims recommended
Below 17°C Cold
Only for hardy swimmers
Cyclades
The Cyclades warm well by summer, but open-water exposure and Meltemi winds can make them feel cooler than headline SST values suggest.
Crete
Crete keeps a long season, especially where sheltered beaches and south-facing coasts retain warmth deep into autumn.
Dodecanese
Rhodes and the southeastern Aegean typically deliver the warmest water in the tool, especially in August through early October.
Ionian Islands
The Ionian often feels gentler earlier and later in the season thanks to calmer conditions and a less exposed swimming experience.
Recent-decade climatology backbone
The monthly values in this tool are built on NOAA OISST v2.1, a long-running 0.25° sea-surface temperature product. We currently ship a recent-decade planning window (2014-2023) rather than an older 1981-2010 style normal.
Mediterranean warming context
Copernicus Marine indicators show that the Mediterranean has warmed materially in recent decades, so recent trip-planning averages are often more useful for travelers than older climatology baselines.
Greek coastal sanity checks
Poseidon/HCMR and HNODC references help validate local interpretation, especially when exposed Aegean islands feel cooler because of wind and open-water mixing while sheltered Ionian or south-facing beaches stay friendlier.
Start with the heatmap if you are deciding when to go. Use the destination details if you already know the island and want better timing or beach expectations.
Sea temperatures are historical averages. Actual conditions vary with wind, depth, and recent weather. Always check local conditions and official beach advisories before swimming.
| Island | Region | jan | feb | mar | apr | may | jun | jul | aug | sep | oct | nov |
|---|
| dec |
|---|
| Santorini | Cyclades | 17.1° | 16.6° | 16.7° | 17.4° | 19.5° | 22.5° | 24.1° | 25.1° | 24.6° | 22.5° | 20.3° | 18.2° |
| Mykonos | Cyclades | 16.8° | 16.1° | 16.2° | 16.9° | 18.9° | 21.9° | 23.6° | 24.4° | 23.8° | 21.5° | 19.2° | 17.6° |
| Crete (North Coast) | Crete | 16.8° | 16.1° | 16.3° | 17.4° | 19.7° | 22.9° | 25.3° |
These answers match the planning questions appearing in Search Console and summarize what the interactive map shows in a faster, citation-ready format.
Greece is coolest from January through March, turns more comfortable from late May into June, peaks in July through September, and often remains swimmable in early October. Use the heatmap above to compare each island group month by month.
Crete and the Dodecanese usually hold the strongest late-season warmth. The Ionian often feels friendly in early summer, while the Cyclades can feel cooler on windy exposed beaches even when the monthly average looks similar.
May is possible for quick swims, especially late in the month and in sheltered bays. Early October is often better because the sea has stored summer heat; late October is less predictable and should be checked against local wind.
No. The tool shows historical monthly averages for trip planning. Use it to pick the right island and month, then check local forecasts, wind, and port or beach notices before making a same-day swim decision.
These takeaways summarize the current planning dataset and the supporting climate research. They are meant to help you choose timing and region, not replace live beach checks.
The following table lists the exact geographic coordinates used as the reference point for the monthly sea surface temperature averages shown for each island.
| Island / Destination | Region | Reference Beach | Coordinates (Lat, Lng) |
|---|---|---|---|
| Santorini | Cyclades | Perissa Beach | 36.3546° N, 25.4735° E |
| Mykonos | Cyclades | Ornos Beach | 37.4230° N, 25.3230° E |
| Crete (North Coast) | Crete | Ammoudara Beach | 35.3390° N, 25.0820° E |
| Rhodes | Dodecanese | Lindos Beach | 36.0910° N, 28.0870° E |
| Corfu | Ionian Islands | Glyfada Beach | 39.5680° N, 19.8540° E |
| Zakynthos | Ionian Islands |
| 26.1° |
| 25.4° |
| 23.2° |
| 20.9° |
| 18.6° |
| Rhodes | Dodecanese | 18.3° | 17.4° | 17.4° | 18.2° | 20.4° | 23.1° | 26.1° | 27.8° | 27° | 24.7° | 22.3° | 19.9° |
| Corfu | Ionian Islands | 16.2° | 15.5° | 15.3° | 16.3° | 18.9° | 22.5° | 24.8° | 26.2° | 25.1° | 23° | 20.7° | 18° |
| Zakynthos | Ionian Islands | 17° | 16.1° | 15.8° | 16.7° | 19.1° | 22.7° | 25.5° | 26.7° | 25.7° | 23.6° | 21.3° | 18.6° |
| Naxos | Cyclades | 16.9° | 16.3° | 16.4° | 17.1° | 19.1° | 22° | 23.6° | 24.4° | 23.9° | 21.6° | 19.4° | 17.8° |
| Paros | Cyclades | 16.7° | 16.2° | 16.3° | 17.1° | 19.2° | 22.2° | 23.9° | 24.7° | 24.1° | 21.8° | 19.5° | 17.7° |
| Crete (South Coast) | Crete | 17.4° | 16.6° | 16.6° | 17.6° | 19.6° | 22.6° | 25° | 26.2° | 25.8° | 24.2° | 22° | 19.4° |
| Laganas Bay |
| 37.7200° N, 20.8720° E |
| Naxos | Cyclades | Agios Prokopios | 37.0800° N, 25.3470° E |
| Paros | Cyclades | Parikia Bay | 37.0500° N, 25.1000° E |
| Crete (South Coast) | Crete | Matala Beach | 34.9930° N, 24.7480° E |
Everything you need to know about sea temperatures and swimming conditions in Greece.