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Guide · Best time
The best time to visit the Blue Cave in Montenegro
The Blue Cave looks its bluest in bright sun and calm water. Here is how the months compare on the coast, when the light inside is strongest, and when the sea is warm enough for a long swim.
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Editorial team, blue-cave-montenegro.comUpdated October 25, 2026about 6 min to read13 sources
Quick answer
- 01Swim season
- May to October, 180 days a year.1
- 02Warmest sea
- 22 to 26 degrees off Herceg Novi from May to September.2
- 03Brightest blue
- Sunny summer days, especially before noon.3
- 04Driest month
- August at Bar: 1 wet day of 2.5 mm or more on average.4
- 05Wettest stretch
- October to December, with 135 to 164 mm a month.4
Three things decide the best day
The best time to visit the Blue Cave in Montenegro comes down to three things: sun for the light, calm water for the boat and warm water for the swim. The light matters most. The municipality of Herceg Novi says the blue is at its strongest on sunny summer days, especially in the morning before noon, when sunlight reflects off the sea through the smaller opening and colours the water and the vault.3
Calm water matters next, because the cave faces the open sea. The booked tour changes its route or offers an alternative when waves on the open sea are too big, and other operators write similar clauses. A sunny day with a strong swell can still keep you away from the entrance, so the calendar can only improve your odds, never guarantee them.
Warm water matters for comfort. The national tourism organisation gives a swimming season of 180 days a year, from May to October.1 Outside those months the swim into the cave becomes a quick, brave dip rather than a slow float.
The year at the cave
When the season starts and ends
-
February
Mimosa Festival
Herceg Novi's winter festival, rarely below 10 degrees.5
-
May
Swim season opens
The season runs May to October.1
-
June
Long days
15.3 hours of daylight at mid-month.4
-
August
Driest month
1 wet day of 2.5 mm or more at Bar.4
-
October
Season ends
Rain rises to 135 mm in the month.4
Summer: the brightest blue and the most boats
July and August are the hottest and driest months on this coast. At the Bar weather station the average high is 30.7 °C in July and 31 °C in August, and August averages just a single wet day of 2.5 mm or more.4 The municipality of Herceg Novi counts 10.7 sunny hours a day in July and August.6 That is exactly the sun the cave needs.
For the water temperature at the Blue Cave, the nearest official figures come from Herceg Novi, which gives 22 to 26 degrees from May to September, and the government's portal for digital nomads says the sea reaches up to 27 degrees.27 In high summer you can stay in the water for the full swim stop without shivering.
The price of summer is company. Tivat Airport says more than 80% of its traffic comes in the summer tourist season, with very distinct peaks.8 Book early and pick a morning departure, which also matches the hours the municipality describes for the best light, and be ready to share the entrance with other boats.
Month by month
Daylight and wet days on the coast
Hours without sunDays with precipitationSeason
The coast in numbers
Weather at Bar, month by month
| Month | Daylight (h) | Darkness (h) | High / low | Wet days | Sea swimming |
|---|---|---|---|---|---|
| Jan | 9.4 | 14.6 | 13 / 7 °C | 8 | |
| Feb | 10.5 | 13.5 | 14 / 7 °C | 7 | |
| Mar | 11.9 | 12.1 | 17 / 9 °C | 7 | |
| Apr | 13.3 | 10.7 | 20 / 11 °C | 7 | |
| May | 14.6 | 9.4 | 24 / 15 °C | 5 | swim season |
| Jun | 15.3 | 8.7 | 28 / 19 °C | 3 | swim season |
| Jul | 15 | 9 | 31 / 21 °C | 2 | swim season |
| Aug | 14 | 10 | 31 / 22 °C | 1 | swim season |
| Sep | 12.6 | 11.4 | 28 / 19 °C | 5 | swim season |
| Oct | 11.1 | 12.9 | 23 / 15 °C | 6 | swim season |
| Nov | 9.8 | 14.2 | 19 / 12 °C | 8 | |
| Dec | 9.1 | 14.9 | 15 / 8 °C | 9 |
Bar, on the open coast 44 km south-east of Kotor: mid-month daylight, the average afternoon high and night low, and the wet days that reach 2.5 mm, our own averages from NOAA records, 1991 to 2020, with gaps filled from the Dubrovnik station.4 Season according to the National Tourism Organisation of Montenegro, which gives the swimming season.1
Three seasons
Early summer, high summer or autumn
Sweet spot
Most sun
QuietestDecision helper
When should you book the Blue Cave?
Match the month to your priorities
With a swimming season that lasts 180 days a year, from May to October, there is plenty of time to plan a vacation!
June and September: the sweet spot
If you can travel outside the school holidays, June and September are hard to beat. June at Bar averages a high of 28.2 °C with 3 days of rain at 2.5 mm or more, and September averages 27.9 °C with 5 such days.4 Both sit inside the Herceg Novi window for water at 22 to 26 degrees.2
Daylight is generous too. Mid-June has 15.3 hours of sun above the horizon at Bar, and mid-September still has 12.6 hours.4 That leaves time for a morning boat to the cave and an afternoon in Perast or on Žanjic beach without rushing.
September does bring a change. Rainfall at Bar jumps from 17 mm in August to 127 mm in September, as the autumn weather starts to arrive on this coast.4 Rain here often comes in a few heavy days rather than a constant drizzle, so a flexible booking with free cancellation is worth more in September than in July.
Checklist
Planning around the weather
01
Before booking
- A morning departure for the best light
- Free cancellation, in case the sea turns
- A spare day for a second try
02
By season
- A light jacket for May and October
- Plenty of water for July and August
- Sun cream on the open deck
Cost calculator
Your Blue Cave trip, any month
Starting totals for the shared boats to the cave.
People
Total from$105
each from $53
Check availabilityfree cancellationA total here is the lowest per-person starting price on GetYourGuide times the size of your group, converted with the European Central Bank's daily reference rate; the date and option you pick set the final amount.
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Montenegro Guide: Where to Stay and When to Go
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May and October: quieter, cooler, less certain
May opens the season. The national tourism organisation gives an average maximum of 19 degrees in May, while the Bar station on the coast records a May average high of 24.2 °C.94 The water is at the cool end of the range, fine for a short swim if you do not mind the first gasp.
October closes it. Bar averages a high of 23.4 °C in October, but rain climbs to 135 mm in the month, and mid-month daylight falls to 11.1 hours.4 The ferry across the bay switches from its summer to its winter timetable in October: in 2026 the summer plan ran until 11 October.10
Both months suit travellers who value space over certainty. The light is softer and the waterfronts are calmer, but the chance of a cancelled cave stop rises with every unsettled day. Keep a spare day in your plans.
Winter on the bay
From November to April the Blue Cave is a different trip. November is the wettest month at Bar, with 164 mm of rain, and December brings 9 wet days of 2.5 mm or more.4 January averages a high of 12.6 °C.4 A swim at the cave in those months is for the brave, and many days the open sea will be too rough anyway.
Winter has its own reasons to come. Herceg Novi holds its Mimosa Festival in February, when temperatures rarely drop below 10 degrees, and the festival has run since 1969.511 The towns are quiet in these months.
If winter is your only chance, plan the cave as a bonus. Book a tour with a clear weather rule, keep the morning free for a second try, and enjoy the bay itself; the views of Perast and the islets do not need summer sun.
Booking so the weather cannot cost you
Whatever the month, book in a way that lets the sea change your plans. The booked tour offers free cancellation up to 24 hours before and lets you reserve now and pay later. Check the forecast a couple of days ahead, and move or cancel while you still can if the wind is building.
Some operators go further when the cave itself is the problem. One Kotor boat lets you postpone or take a full refund if the weather stops the tour. A Tivat day cancels and refunds in full whenever the weather does not allow entry to the Blue Cave. The full-day catamaran may replace the cave visit with another activity on a bad day or let you opt for a full refund.
The beaches follow the same calendar. On organised bathing areas Montenegro's coastal agency requires one lifeguard per 50 m of shore in July and August and one per 100 m in May, June, September and October.12 Its sea water monitoring runs every fifteen days through the bathing season from May to October.13 Those months are when the coast is fully open for swimmers.
The best hour of the day
The hour you reach the cave counts as much as the month. The municipality's description is precise: the effect is strongest on sunny summer days, especially in the morning, before noon.3 An early departure from Kotor reaches the cave after the stops on the way, so on a 3-hour loop the timing of your start decides the light you get.
On the booked tour the cave is the last stop, after Perast, the islet, the tunnel and Mamula. A boat that leaves Kotor at the start of the day therefore reaches the cave later in the morning. Some tours run to the cave first; one Kotor loop starts with the Blue Cave and only then works back through the bay.
Afternoon tours are not wasted. The cave still glows on a sunny afternoon, just with a softer tone, and the late light on the walls of Perast and the islet of Our Lady can be lovely. If the cave is your priority, though, choose a morning slot and a sunny forecast.
Into the blue
Church, tunnel, fortress, then a swim
3 hours by speedboat from Kotor, with an optional 30-minute swim at the cave.
You ask,we answer.
What is the best month for the Blue Cave in Montenegro?
June or September. Both are warm, with water at 22 to 26 degrees and few wet days at Bar.24
What time of day is best for the Blue Cave?
Morning, before noon. The light is strongest then on sunny summer days.3
When is the swimming season in Montenegro?
May to October. The national tourism organisation gives 180 days a year.1
How warm is the water near the Blue Cave in summer?
22 to 26 degrees. Herceg Novi gives that range from May to September.2
Which month has the least rain?
August. In August Bar sees a single wet day of 2.5 mm or more on average.4
Can I visit the Blue Cave in winter?
Sometimes, if the sea allows. November is the wettest month at Bar, with 164 mm of rain.4
Do rough seas cancel the cave?
They can. The booked tour changes its route or offers another tour when waves are too big.
Sources
Where the information comes from
- 1National Tourism Organisation of MontenegroVacations on Montenegro's Adriatic coast↩
- 2Municipality of Herceg Novi (official website)Sights↩
- 3Municipality of Herceg Novi (Opština Herceg Novi)Novska rivijera i Orjen↩
- 4↩
- 5Herceg Novi Tourist Board (Turistička organizacija Herceg Novi)Zimske čarolije↩
- 6Municipality of Herceg Novi (official website)Sights↩
- 7Government of Montenegro (digitalnomads.gov.me)Sunny days↩
- 8Airports of Montenegro (Aerodromi Crne Gore)Tivat Airport History↩
- 9National Tourism Organisation of MontenegroThe best period to visit Montenegro↩
- 10Javno preduzeće za upravljanje morskim dobrom Crne Gore (Trajekt Kamenari - Lepetane)Red vožnje↩
- 11Herceg Novi Tourist Board (Turistička organizacija Herceg Novi)Mimosa festival↩
- 12Javno preduzeće za upravljanje morskim dobrom Crne Gore (Morsko dobro)Spasilačka služba na kupalištima↩
- 13Javno preduzeće za upravljanje morskim dobrom Crne Gore (Morsko dobro)Praćenje kvaliteta morske vode↩
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