Your September weather guide
WarmWeather in Split in September
September is a good choice for Split if you want warm days and swimming weather without relying on intense heat. Average daytime highs are around 24°C, nights fall to around 17°C, and the sea averages 22.4°C. That suits a holiday mixing time outdoors with dips in the sea, rather than one built around guaranteed hot sunshine. The catch is rain: keep your plans flexible and pack something for cooler evenings.
Long-term climate averages for Split, not a forecast · 1991-2020
Split, month by month
Your snapshot
At a glance
The useful details for Split.
- Average daytime high
- 24.3°C
- 9 in 10 days stay below 28°C
- Average night-time low
- 16.7°C
- coldest 10% of nights: 13°C or lower
- Compared with London
- +5.7°C
- London averages 18.6°C in September
- Sea temperature
- 22.4°C
- year to year: 21°C to 24°C
- Sunshine per day (est.)
- 7.6h
- 62% of 12.3 h of daylight
- Rainy days (1 mm+)
- 8
- 104 mm over the month
- Humidity
- 69%
- Days over 25°C
- 43%
- 3% over 30°C
- Record high 1991-2020
- 32.7°C
- 2020-09-10
- Record low 1991-2020
- 7.7°C
- 1995-09-30
- Flight from London
- ≈ 2 h 36 min
- 1508 km, short-haul (estimate for a direct flight)
Records are observed extremes within 1991-2020, not typical holiday conditions. Warm-day percentages are shares of days, not day counts.
How September compares
September is the 4th warmest month of the year in Split and ranks 107th of 134 destinations we compare for September - see where else is hot in September. Within Croatia it is 2nd of 4 (Croatia in September). Against London's average high of 18.6°C in September, Split is 5.7°C warmer by day and 5.5°C warmer at night.
Daytime and night-time in September
The typical September day in Split peaks at 24.3°C, but that is an average: the warmest 10% of days reach 28.2°C or more. Roughly 1 in 2 days top 25°C and 1 in 29 pass 30°C. Nights average 16.7°C; one night in ten drops to 12.8°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 32.7°C (2020-09-10) and the coldest night 7.7°C (1995-09-30).
Rain in September
Some rain (4-8 rainy days): about 8 days with 1 mm or more, 104 mm in total. Year to year it varies a lot - the wettest September was 1996 with 222 mm, the driest 1991 with 12 mm. Humidity averages 69%.
Sea temperature in September
The sea averages 22.4°C - warm enough to swim (22°c+). Depending on the year it ranges from 21.2°C to 24.0°C. For the warmest sea here, come in August (24.6°C).
Sunshine and daylight
Around 7.6 hours of sunshine a day (estimated from cloud cover), 12.3 hours of daylight: the sun rises about 06:34 and sets about 19:05 local time in mid-September. Average cloud cover is 38%.
Is September a good time to visit Split?
Yes - it is one of the better months: warm days, manageable rain and long sunny days. The best months for Split on our scoring are August, July, June; months averaging 25°C or more: Jun, Jul, Aug.
Warm days, cooler evenings
Expect warmth rather than persistent heat. Days reach 25°C on 43% of occasions, while 30°C is reached on just 3%, so September suits travellers who find very hot weather tiring. Midday can still feel hot in direct sunshine, making light clothing and sun protection sensible. For evenings, bring a jumper or light jacket rather than packing only summer clothes. The coldest nights fall to around 13°C or below, so an outdoor dinner may call for an extra layer. If your priority is stronger heat, the weather scores favour August, July and June over September.
Leave room for wet weather
Rain is a meaningful part of the September picture, with about 8 rainy days, so a completely dry stay is not something to count on. A light waterproof is useful, and it makes sense to keep your outdoor plans movable rather than tying everything to a fixed day. There is still a worthwhile amount of sunshine between any wet weather, but the monthly averages cannot tell you how rain will fall during your visit. September is therefore a better fit for someone happy to adapt than for a traveller whose holiday depends on uninterrupted time in the sun.
A little perspective
Split through the year
September is highlighted. See how it compares with the rest of the year.
| Month | Day | Night | Sea | Sun/day | Rain mm | Rainy days | Days 25°C+ |
|---|---|---|---|---|---|---|---|
| January | 10.1°C | 3.8°C | 13.7°C | 4.2 | 120 | 11 | 0% |
| February | 10.9°C | 3.8°C | 12.7°C | 5.0 | 106 | 10 | 0% |
| March | 13.8°C | 6.4°C | 12.8°C | 5.8 | 103 | 10 | 0% |
| April | 17.2°C | 9.6°C | 14.2°C | 6.5 | 100 | 11 | 1% |
| May | 21.7°C | 13.9°C | 17.8°C | 7.8 | 74 | 9 | 14% |
| Junebest | 26.0°C | 17.9°C | 21.7°C | 9.9 | 42 | 7 | 62% |
| Julybest | 29.0°C | 20.3°C | 24.0°C | 11.6 | 27 | 5 | 92% |
| Augustbest | 29.3°C | 20.7°C | 24.6°C | 10.6 | 41 | 5 | 94% |
| SeptemberSelected | 24.3°C | 16.7°C | 22.4°C | 7.6 | 104 | 8 | 43% |
| October | 19.9°C | 13.0°C | 20.3°C | 5.7 | 137 | 11 | 2% |
| November | 15.1°C | 9.2°C | 18.0°C | 4.0 | 226 | 14 | 0% |
| December | 11.2°C | 5.2°C | 15.7°C | 4.0 | 175 | 12 | 0% |
Day = average daytime high, night = average night-time low, 1991-2020.Sun is hours per day; rainy days count 1 mm or more.
Day, night and sea
Monthly average temperatures, 1991-2020
- Day
- Night
- Sea
Best months here
On warmth, low rainfall and sunshine, start with these.
Keep exploring
Similar in September
Closest matches on daytime temperature, sea temperature and sunshine, in other countries.
Spain · 25°C by day · sea 23°C
Lanzarote
Turkey · 24°C by day · sea 23°C
Istanbul
Spain · 25°C by day · sea 23°C
Fuerteventura
Montenegro · 25°C by day · sea 24°C
Budva
France · 24°C by day · sea 23°C
Nice
A little more detail
Split in September FAQs
Plain answers, grounded in the averages.
Is Split hot in September?
Split is warm in September: the average daytime high is 24.3°C and nights average 16.7°C. Roughly 1 in 2 September days reach 25°C.
Can you swim in the sea in Split in September?
The sea around Split averages 22.4°C in September, which is warm enough for most people to swim comfortably. Between 1991 and 2020 it ranged from 21°C to 24°C depending on the year.
How much does it rain in Split in September?
Split sees about 8 rainy days (1 mm or more) and 104 mm of rain in a typical September. The wettest September between 1991 and 2020 was 1996 (222 mm) and the driest was 1991 (12 mm).
How sunny is Split in September?
Split gets around 7.6 hours of sunshine a day in September out of 12.3 hours of daylight (estimated from average cloud cover).
How does Split compare with the UK in September?
Split is on average 5.7°C warmer than London by day in September (24.3°C against 18.6°C).
What is the hottest September on record in Split?
Between 1991 and 2020 the hottest September day in Split reached 32.7°C on 2020-09-10, and the coldest night dropped to 7.7°C on 1995-09-30.
Is the sea warm enough for swimming?
Yes. The sea averages 22.4°C, which is warm enough for swimming, though it may feel fresh when you first get in. The September average varies from 21°C to 24°C between years, so some visits will feel more comfortable than others.
How much warmer is Split than London in September?
Split's average daytime high is 24.3°C, compared with London's 18.6°C - a difference of 5.7°C. That is a noticeable step up in daytime warmth for a UK traveller, although cooler evenings still make an extra layer useful.
How much sunshine can I expect?
September averages about 7.6 hours of sunshine within 12.3 hours of daylight. That leaves plenty of scope for time outdoors, but it does not mean every day will be clear. Keep some flexibility for cloud and rain.
About these averages
ERA5-Land climate reanalysis via Open-Meteo (11 km grid) and NOAA Coral Reef Watch 5 km sea temperatures, 1991-2020
Averages computed from daily values at Split. Sea temperature from the nearest 5 km sea cell, 2.1 km from that point. Sunshine hours are estimated from average cloud cover.Records are the highest and lowest daily values in that 30-year period, not all-time records. These are climate averages, not a forecast for your trip. How we measure holiday weather
- Hot · 25°C+
- Warm · 20°C to below 25°C
- Mild · 15°C to below 20°C
- Cool · below 15°C