Spain

Best Time to Dive in Costa Brava / Medes

42.05°N 3.22°E

Aim for May to September once the water has warmed to 21 °C from 15. The marine life holds steady all year, so the weather picks the month.

Best time
May–Sep
Water
1324 °C
Visibility
520 m
Dived from
day boat
Tidal range
0.10.2 m
Species logged
4

Worth knowing: 31% of days see seas over 1.5 m.

Where it is

Spain
25 kmN

111 km across · coastline from Natural Earth 10m

Diving in Costa Brava / Medes — monthly breakdown

Best months at this destination

A year of scuba diving conditions at a glance. Hover a month to isolate it.

Month by month conditions, water temperature, visibility and marine life
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
ConditionsModeratePoorPoorPoorExcellentExcellentExcellentExcellentGoodModeratePoorModerate
Water temp (°C)141313141721232422201715
Visibility (m)51551551551551551551510201020515515515
Marine lifePeakBusySteadyBusyPeakBusyPeakSteadySteadySteadyBusyPeak
Best timePeakPeakPeakPeakPeak
Excellent Good Moderate PoorPeak season May–Sep

Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.

The Costa Brava / Medes diving season

3 seasons

February to April · Off season

3 months
Water temperature
1314 °C
Visibility
515 m
Rain
7 days a month

Diving conditionsThe sea is rougher. The wind is up.

May to September · Peak season

5 months
Water temperature
1724 °C
Visibility
515 m
Rain
5 days a month

Diving conditionsThe sea is calmer. The wind eases.

Marine lifeGiant devil ray (hit-or-miss), Ocean sunfish (near-guaranteed) peak at Costa Brava / Medes in these months.

October to January · Shoulder season

4 months
Water temperature
1420 °C
Visibility
515 m
Rain
7 days a month

Diving conditionsThe wind is up. The sea is rougher.

Marine lifeOcean sunfish (near-guaranteed) peaks at Costa Brava / Medes in these months.

  • Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
  • Visibility is estimated from satellite chlorophyll-a.

Costa Brava / Medes water temperature and weather

385 underwater observation records · 21 surveyed years of ocean data · 10 years of sea temperature

Water & weather

Costa Brava / Medes water temperature by month

The dashed line is the monthly average. Eight days in ten fall inside the band.

1214161820222426JanFebMarAprMayJunJulAugSepOctNovDecSea temperature (°C)

10th to 90th percentile rangemonthly mean

6
rough days a month

Seas top 1.5 m on 19% of days. Enough to cancel a day boat

1
blowy days a month

Gusts over 40 km/h, about where a day boat stays in port

6
wet days a month

1 of them bring heavy rain

Monthly sea state, wind, rain, air temperature and daylight
MonthSwellGusts over 40 km/hWet daysHeavy rainAirDaylight
January2.3 m12%6213 °C9.3 h
February2.1 m7%6214 °C10.4 h
March2.3 m7%9116 °C11.7 h
April2.0 m4%7218 °C13.1 h
May1.3 m2%9122 °C14.4 h
June1.2 m0%5126 °C15.1 h
July1.4 m0%2129 °C14.8 h
August1.4 m1%3129 °C13.7 h
September1.5 m2%8125 °C12.3 h
October1.6 m4%8222 °C10.8 h
November2.1 m6%8217 °C9.6 h
December1.9 m8%7214 °C8.9 h

Swell is the rough end of the month: nine days in ten come in under it. Sea temperature covers 10 years, waves 4.

Pick your week

48 weeks from the daily record. Darker is better, against this site's own year. Pick a month for the detail.

Conditions by week, four weeks per month
Week 1January week 1: ModerateFebruary week 1: ModerateMarch week 1: ModerateApril week 1: PoorMay week 1: GoodJune week 1: GoodJuly week 1: ExcellentAugust week 1: GoodSeptember week 1: ExcellentOctober week 1: GoodNovember week 1: PoorDecember week 1: Poor
Week 2January week 2: ModerateFebruary week 2: PoorMarch week 2: ModerateApril week 2: ModerateMay week 2: GoodJune week 2: GoodJuly week 2: ExcellentAugust week 2: ExcellentSeptember week 2: ExcellentOctober week 2: GoodNovember week 2: PoorDecember week 2: Moderate
Week 3January week 3: ModerateFebruary week 3: ModerateMarch week 3: ModerateApril week 3: PoorMay week 3: ExcellentJune week 3: ExcellentJuly week 3: ExcellentAugust week 3: ExcellentSeptember week 3: ModerateOctober week 3: PoorNovember week 3: ModerateDecember week 3: Moderate
Week 4January week 4: PoorFebruary week 4: ModerateMarch week 4: PoorApril week 4: PoorMay week 4: ExcellentJune week 4: ExcellentJuly week 4: GoodAugust week 4: GoodSeptember week 4: ExcellentOctober week 4: PoorNovember week 4: ModerateDecember week 4: Poor
Excellent Good Moderate PoorBest week to go: fourth of June

June, week by week

WeekConditionsWaterSwellWindRain chance
Week 1Good19 °C1.1 m21 km/h23%
Week 2Good20 °C1.1 m21 km/h21%
Week 3Excellent21 °C1.2 m21 km/h15%
Week 4Excellent22 °C1.3 m21 km/h9%

10 years of daily records, averaged into weeks.

Gear & storms

What to wear

Off the coldest water of each month, not the average — that is what the suit has to cope with.

Wetsuit thickness by month
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
SuitJanuary: 7 mmFebruary: dryMarch: dryApril: 7 mmMay: 7 mmJune: 5 mm +July: 5 mmAugust: 5 mmSeptember: 5 mmOctober: 5 mm +November: 7 mmDecember: 7 mm
  • Nov–Jan7 mm semi-dry
  • Feb–Mardrysuit
  • Apr–May7 mm semi-dry
  • Jun5 mm with hood and gloves
  • Jul–Sep5 mm full suit
  • Oct5 mm with hood and gloves

Swell through the year

The rough end of each month — nine days in ten come in under it.

JanJanuary: 2.3 metresFebFebruary: 2.1 metresMarMarch: 2.3 metresAprApril: 2.0 metresMayMay: 1.3 metresJunJune: 1.2 metresJulJuly: 1.4 metresAugAugust: 1.4 metresSepSeptember: 1.5 metresOctOctober: 1.6 metresNovNovember: 2.1 metresDecDecember: 1.9 metres

Amber is over 1.5 m.

Tides

springs 0.3 mneaps 0.1 mneapsone lunar month
Daily tidal range across one lunar month.

Tropical storms

No tropical storm has come within 250 km in 30 years of records. Swell and wind set the season, not cyclones.

  • NOAASea surface temperature, from OISST and MUR
  • ERA5Wind, waves, rain and air temperature, via Open-Meteo
  • OBISMarine species records within 60 km
  • IBTrACSTropical cyclone tracks, 1996 to 2025

Costa Brava / Medes marine life — what you'll see diving

385 records within 60 km
SpeciesWhenObserved windowReliabilityEvidenceRecords
Bottlenose dolphinJan, Jul, NovNear-guaranteed
18/21
48
Giant devil rayJunHit-or-miss
5/21
9
Ocean sunfishDec–Jan, MayNear-guaranteed
13/21
131
Loggerhead turtleJul, OctHit-or-miss
6/21
187
Peak Present
Observed window
Months with records. Peak is where most of them fall.
Reliability
  • Near-guaranteed in 60% of surveyed years or more
  • Likely 30% to 60%
  • Hit-or-miss under 30%
Evidence
Years it was seen, out of the years anyone surveyed.
Records
OBIS sightings within 60 km.

These are sightings people logged, not a full survey of the reef. A species missing from a month may just mean nobody recorded one.

Diving Costa Brava / Medes — common questions

When is the best time to dive Costa Brava / Medes?
Aim for May to September once the water has warmed to 21 °C from 15. The marine life holds steady all year, so the weather picks the month.
When is the diving season in Costa Brava / Medes?
The diving season in Costa Brava / Medes runs May to September.
Is the diving in Costa Brava / Medes good for beginners?
Yes. It suits Open Water divers, so it works for a first trip after certification.
How warm is the water in Costa Brava / Medes?
Between 13 and 24 °C at the surface across the year, coldest in February and warmest in August. It runs cooler below the thermocline.
What wetsuit do I need in Costa Brava / Medes?
A drysuit covers the coldest water of the year. In the warmest months a 5 mm full suit is enough.
What is the visibility like in Costa Brava / Medes?
Roughly 5 to 20 m depending on the month. That is estimated from satellite chlorophyll-a rather than measured in the water.
What will I see diving Costa Brava / Medes?
The most consistently recorded species are Bottlenose dolphin (near-guaranteed), Giant devil ray (hit-or-miss) and Ocean sunfish (near-guaranteed), from 385 records within 60 km.
Does Costa Brava / Medes get tropical storms?
No. None has passed within 250 km in 30 years of records.
Is there current in Costa Brava / Medes?
The tide rises and falls 0.2 m around the full and new moon, against 0.1 m in between. How much of that becomes current depends on the shape of the channel.
When should I avoid Costa Brava / Medes?
February–March are the weakest months for conditions.
How do you dive Costa Brava / Medes?
Mostly from day boats. Trips run through the season, May–Sep.