Bissau, Guinea-Bissau Climate & Monthly Averages
Bissau has a tropical wet-and-dry climate. June is the hottest month, averaging 88° by day; August is the coldest at 83°.
Rain, not cold, divides the year in Bissau
Bissau has one of the steadier climates in our dataset. Average highs move only 2°C across the whole year - from 83°F (28°C) in August to 88°F (31°C) in June - so the practical difference between seasons here is rainfall and daylight, not warmth.
The wet-and-dry rhythm at a glance
7 months average under 20 mm of rain, the longest unbroken stretch running November through May. August sits at the other end of the year: 83°F (28°C) by day, 76°F (25°C) at night. Warmth peaks in June: highs of 88°F (31°C), lows of 78°F (25°C). The gridded 2015-2024 daily record for this location tops out at 105°F (40°C) and bottoms at 65°F (18°C) - decade extremes, not all-time station records.
Relative humidity averages 67% across the year, drier than about 75% of the cities we track.
April is the brightest month at 11.7 hours of sun a day, against an annual average of 9.9. Rainfall is strongly seasonal: 85% of the annual total falls in the July to September window, leaving January at less than 1 mm. Between the average June and the average August lie 2°C, a narrower spread than all but 3% of the 3496 cities in our dataset.
More climate facts for Bissau
- Hottest month: June - highs near 88°F (31°C)
- Coldest month: August - highs near 83°F (28°C)
- Decade extremes (2015-2024): 105°F (40°C) high · 65°F (18°C) low
- Wettest month: August (29 rainy days) · Sunniest: April (11.7 h sun/day)
- Climate type: tropical wet-and-dry
- Annual swing: 2°C between the average warmest and coolest month · day to night: 8°C
- Months averaging 30°C or hotter: 9
- Average humidity: 67%
Choosing the right part of the year in Bissau
Choose dates by rain, not just temperature
Aim for November to January and April to May if you get the choice: the rains have stopped and the heat has not yet peaked, and highs average 91°F (33°C) against roughly 1 wet days a month. For the same question asked the other way round, see where else is warm in November.
What the humidity changes
Pack for Bissau with light clothing for the warm months and a compact umbrella or rain shell. June nights average 78°F (25°C), so evenings rarely match the afternoons.
Warm all year: the monthly rain pattern
Each card shows the average high and low. The bar places that month between Bissau's coldest night and warmest afternoon.
January
- Rain
- 0 days
- Sunshine
- 10.5 h
- Daylight
- 11.5 h
February
- Rain
- 0 days
- Sunshine
- 10.8 h
- Daylight
- 11.7 h
March
- Rain
- 0 days
- Sunshine
- 11.2 h
- Daylight
- 12.0 h
April
- Rain
- 0 days
- Sunshine
- 11.7 h
- Daylight
- 12.4 h
May
- Rain
- 1 day
- Sunshine
- 11.2 h
- Daylight
- 12.7 h
June
- Rain
- 10 days
- Sunshine
- 10.2 h
- Daylight
- 12.8 h
July
- Rain
- 28 days
- Sunshine
- 7.8 h
- Daylight
- 12.8 h
August
- Rain
- 29 days
- Sunshine
- 7.5 h
- Daylight
- 12.5 h
September
- Rain
- 26 days
- Sunshine
- 8.2 h
- Daylight
- 12.2 h
October
- Rain
- 20 days
- Sunshine
- 9.7 h
- Daylight
- 11.8 h
November
- Rain
- 4 days
- Sunshine
- 10.4 h
- Daylight
- 11.6 h
December
- Rain
- 0 days
- Sunshine
- 10.1 h
- Daylight
- 11.4 h
Looking for warmer alternatives? Browse warm places by month, or compare Bissau's coolest part of the year: August, July, September.
Monthly temperature and rain table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 91° | 70° | 0 | 0.0 in | 10.5 h/day | 11.5 h | 0% | 43% |
| February | 93° | 71° | 0 | 0.0 in | 10.8 h/day | 11.7 h | 0% | 44% |
| March | 93° | 73° | 0 | 0.0 in | 11.2 h/day | 12.0 h | 0% | 52% |
| April | 91° | 74° | 0 | 0.0 in | 11.7 h/day | 12.4 h | 0% | 60% |
| May | 90° | 75° | 1 | 0.1 in | 11.2 h/day | 12.7 h | 2% | 66% |
| June | 88° | 78° | 10 | 2.4 in | 10.2 h/day | 12.8 h | 32% | 76% |
| July | 83° | 77° | 28 | 16.5 in | 7.8 h/day | 12.8 h | 90% | 85% |
| August | 83° | 76° | 29 | 19.9 in | 7.5 h/day | 12.5 h | 93% | 87% |
| September | 84° | 76° | 26 | 13.2 in | 8.2 h/day | 12.2 h | 88% | 87% |
| October | 87° | 77° | 20 | 5.7 in | 9.7 h/day | 11.8 h | 65% | 85% |
| November | 89° | 75° | 4 | 0.7 in | 10.4 h/day | 11.6 h | 12% | 72% |
| December | 91° | 71° | 0 | 0.0 in | 10.1 h/day | 11.4 h | 1% | 49% |
How Bissau compares for rain and warmth
- 85% of the year's precipitation falls in its wettest three months - more seasonal than any other city in our 3496-city dataset.
- Bissau averages 81°F (27°C) across the year - warmer than 94% of the 3496 cities we track.
These comparisons use the same ten-year window for every city in the dataset.
How the calendar changes in warm-weather Bissau
March through May
March through May in Bissau is hot, with daytime highs averaging 91°F (33°C) and nights around 74°F (23°C); precipitation is essentially absent. Daylight is generous - around 11.4 hours of sun a day.
June through August
Through June through August, Bissau brings hot afternoons: 85°F (29°C) by day, 77°F (25°C) after dark, and rain falls on around 66 of the 90 days.
September through November
September through November in Bissau runs hot, with daytime highs averaging 87°F (30°C) and nights around 76°F (25°C); rain falls on around 50 of the 90 days.
December through February
Through December through February, Bissau brings serious heat: 92°F (33°C) by day, 71°F (22°C) after dark, and precipitation is essentially absent. Daylight is generous - around 10.5 hours of sun a day.
Questions about heat and rain in Bissau
When is the rainy season in Bissau?
Is Bissau cold in winter?
How hot does Bissau get in summer?
How sunny is Bissau?
How humid does Bissau get?
Bissau temperature extremes in the 2015–2024 dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.