Bissau weather in August

In August, Bissau has daytime highs averaging 28 °C, nights around 24 °C, with 29 wet days, and a sea temperature of 28 °C. Figures are 1991–2020 climate normals.

  1. Jan 26°
  2. Feb 27°
  3. Mar 28°
  4. Apr 28°
  5. May 28°
  6. Jun 28°
  7. Jul 26°
  8. Aug 26°
  9. Sep 26°
  10. Oct 27°
  11. Nov 28°
  12. Dec 26°

Daily temperatures through August

22°27°31°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 28.8 °C and lows bottom out at 24.0 °C.

How August develops

Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.

DaysAvg highAvg lowChance of rain
1–10 August28.4 °C24.3 °C93 %
11–20 August28.2 °C24.3 °C95 %
21–31 August28.4 °C24.2 °C94 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in August. Wettest date over the 30 years: August 15, at 100 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical August Share of the month
Days above 25 °C 31 of 31 99 %
Days above 30 °C 1.8 of 31 6 %
Days below 0 °C 0 of 31 0 %
Days with more than 1 mm rain 29 of 31 94 %

Conditions in August

MeasureAverage
Mean temperature 26 °C
Record high (1991–2020) 32 °C
Record low (1991–2020) 23 °C
Relative humidity 87 %
Wind speed 17 km/h
Cloud cover 86 %

Where Bissau ranks in August

RankingPositionValue
Warmest sea temperatures in Africa in August17thof 5028 °C

August compared with the months around it

Month Avg high Rainfall Cloud
June 31.5 °C 86 mm 71 %
July 28.9 °C 345 mm 83 %
August 28.3 °C 446 mm 86 %
September 29.0 °C 306 mm 83 %
October 30.3 °C 141 mm 64 %

See all twelve months for Bissau

Nearby destinations in August

Destination Avg high Wet days Sea
Bissau 28 °C 29 28
Ziguinchor 29 °C 28
Banjul 29 °C 23 28
Serekunda 28 °C 23 28
Kaolack 31 °C 20

QuestionsAugust in Bissau, answered

How warm is Bissau in August?

Daily highs average 28 °C and nights fall to about 24 °C, a spread of 4.1 °C between afternoon and dawn. That makes August the 12th warmest month of the year here.

Does it rain much in Bissau in August?

August averages 446 mm of rain, spread over about 29 of the 31 days — 94 % of the month. Cloud cover averages 86 % of the sky.

Is the sea warm enough to swim in August?

The sea averages 28 °C off Bissau in August. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.

How long are the days in August?

Bissau averages 13 hours between sunrise and sunset in August. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.

Data sources and method

Normal period
1991–2020
Dataset version
era5-1991-2020-scores1.1
Last processed

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.