Your September weather guide
HotWeather in Sal in September
September is a good choice for Sal if you want warm swimming weather and can tolerate humidity, but it is less suitable if you need cool nights or guaranteed dry days. Average daytime highs are 26.9°C, nights stay around 25.5°C and the sea averages 26.6°C. For a UK traveller, that means a clear step up in warmth without daytime temperatures routinely becoming extreme. The main catches are sticky evenings and some rain.
Long-term climate averages for Santa Maria, not a forecast · 1991-2020
Sal, month by month
Your snapshot
At a glance
The useful details for Santa Maria.
- Average daytime high
- 26.9°C
- 9 in 10 days stay below 29°C
- Average night-time low
- 25.5°C
- coldest 10% of nights: 25°C or lower
- Compared with London
- +8.3°C
- London averages 18.6°C in September
- Sea temperature
- 26.6°C
- year to year: 26°C to 27°C
- Sunshine per day (est.)
- 6.5h
- 54% of 12.1 h of daylight
- Rainy days (1 mm+)
- 5
- 30 mm over the month
- Humidity
- 82%
- Days over 25°C
- 99%
- 6% over 30°C
- Record high 1991-2020
- 32.1°C
- 2018-09-27
- Record low 1991-2020
- 23.4°C
- 2017-09-26
- Flight from London
- ≈ 6 h 12 min
- 4338 km, mid-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 1st warmest month of the year in Sal and ranks 65th of 134 destinations we compare for September - see where else is hot in September. Within Cape Verde it is 2nd of 2 (Cape Verde in September). Against London's average high of 18.6°C in September, Sal is 8.3°C warmer by day and 14.3°C warmer at night.
Daytime and night-time in September
The typical September day in Sal peaks at 26.9°C, but that is an average: the warmest 10% of days reach 29.2°C or more. About 99% of days top 25°C and 1 in 17 pass 30°C. Nights average 25.5°C; one night in ten drops to 24.6°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 32.1°C (2018-09-27) and the coldest night 23.4°C (2017-09-26).
Rain in September
Some rain (4-8 rainy days): about 5 days with 1 mm or more, 30 mm in total. Year to year it varies a lot - the wettest September was 2009 with 110 mm, the driest 2017 with 1 mm. Humidity averages 82%.
Sea temperature in September
The sea averages 26.6°C - warm enough to swim (22°c+). Depending on the year it ranges from 25.9°C to 27.3°C. This is the warmest the sea gets here all year.
Sunshine and daylight
Around 6.5 hours of sunshine a day (estimated from cloud cover), 12.1 hours of daylight: the sun rises about 06:20 and sets about 18:34 local time in mid-September. Average cloud cover is 46%.
Is September a good time to visit Sal?
Yes - it is one of the better months: hot days, manageable rain. The best months for Sal on our scoring are July, October, November; months averaging 25°C or more: Aug, Sep, Oct, Nov.
Warm days, with little relief at night
September is Sal's warmest month, though the heat is generally more about persistence than extreme afternoon temperatures. Days reach 30°C only 6% of the time, but humidity of 82% can make conditions feel sticky. Compared with London's September daytime high of 18.6°C, Sal is 8.3°C warmer, so pack for summer rather than a British autumn. Loose, breathable clothes make sense, and you may prefer to keep strenuous activity away from midday. Nights bring little cooling, making air conditioning a sensible accommodation priority if you struggle to sleep in warmth. This suits travellers who enjoy sustained heat; it is less appealing if a fresh evening is part of your ideal holiday.
Good for swimming, but allow for cloud and rain
The sea is comfortably warm for swimming, so September suits a holiday built around time in the water. Sunshine averages about 6.5 hours within 12.1 hours of daylight: expect sunny periods, not an uninterrupted blue sky. There are about 5 rainy days, enough to make flexible plans useful without treating the month as a washout. A light waterproof is sensible, but heavy rainwear would be uncomfortable in the humidity. Keep outdoor plans movable rather than relying on every day being dry. The balance works well if warm water matters more to you than consistently clear skies. If rain would spoil the trip for you, September is a compromise rather than an obvious choice.
A little perspective
Sal 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 | 22.4°C | 21.0°C | 22.7°C | 5.9 | 5 | 1 | 6% |
| February | 21.9°C | 20.5°C | 21.9°C | 6.4 | 2 | 0 | 5% |
| March | 21.9°C | 20.5°C | 21.8°C | 7.1 | 1 | 0 | 5% |
| April | 22.2°C | 20.8°C | 22.2°C | 6.7 | 1 | 0 | 7% |
| May | 22.7°C | 21.4°C | 22.5°C | 7.6 | 0 | 0 | 10% |
| June | 23.4°C | 22.2°C | 22.9°C | 8.3 | 0 | 0 | 13% |
| Julybest | 24.7°C | 23.3°C | 24.1°C | 7.1 | 2 | 1 | 30% |
| August | 26.3°C | 24.8°C | 25.9°C | 6.4 | 16 | 3 | 88% |
| SeptemberSelected | 26.9°C | 25.5°C | 26.6°C | 6.5 | 30 | 5 | 99% |
| Octoberbest | 26.6°C | 25.2°C | 26.6°C | 6.3 | 16 | 2 | 93% |
| Novemberbest | 25.4°C | 24.1°C | 25.8°C | 5.3 | 4 | 1 | 56% |
| December | 23.7°C | 22.5°C | 24.1°C | 5.5 | 3 | 1 | 14% |
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.
A little more detail
Sal in September FAQs
Plain answers, grounded in the averages.
Is Sal hot in September?
Sal is hot in September: the average daytime high is 26.9°C and nights average 25.5°C. About 99% of September days reach 25°C or more.
Can you swim in the sea in Sal in September?
The sea around Sal averages 26.6°C in September, which is warm enough for most people to swim comfortably. Between 1991 and 2020 it ranged from 26°C to 27°C depending on the year.
How much does it rain in Sal in September?
Sal sees about 5 rainy days (1 mm or more) and 30 mm of rain in a typical September. The wettest September between 1991 and 2020 was 2009 (110 mm) and the driest was 2017 (1 mm).
How sunny is Sal in September?
Sal gets around 6.5 hours of sunshine a day in September out of 12.1 hours of daylight (estimated from average cloud cover).
How does Sal compare with the UK in September?
Sal is on average 8.3°C warmer than London by day in September (26.9°C against 18.6°C).
What is the hottest September on record in Sal?
Between 1991 and 2020 the hottest September day in Sal reached 32.1°C on 2018-09-27, and the coldest night dropped to 23.4°C on 2017-09-26.
Will I need warm clothes in the evening?
Usually not for the temperature alone: average night lows are 25.5°C, so evenings remain warm. Prioritise light, breathable clothing. A light layer may still be useful in air-conditioned spaces, but outdoor conditions offer little respite from the daytime warmth.
How long is the flight from London?
The flight from London is about 6 h 12 min, putting Sal in mid-haul territory. The weather payoff in September is warmer days than London and a sea suitable for swimming, balanced against humidity and some rain.
Is September the best month to visit Sal?
September is the warmest month, but July, October and November are better overall choices for weather. Choose September if sustained warmth and comfortable swimming matter most; consider those alternatives if you have flexibility and want a better overall weather balance.
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 Santa Maria. Sea temperature from the nearest 5 km sea cell, 3.3 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