The best time to visit Guinea-Bissau is Nov–Jan. It is the only stretch of the year — 3 months — rated go on both daytime heat and rainfall.
Summer monsoon
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 29.5 | 85 | 1% | Go |
| February | 32.4 | 90 | 0% | Fair |
| March | 35.2 | 95 | 0% | Too hot |
| April | 36.7 | 98 | 0% | Too hot |
| May | 36.1 | 97 | 11% | Too hot |
| June | 32.3 | 90 | 63% | Too wet |
| July | 29.2 | 85 | 95% | Too wet |
| August | 28.5 | 83 | 98% | Too wet |
| September | 28.8 | 84 | 98% | Too wet |
| October | 29.7 | 85 | 71% | Too wet |
| November | 30.1 | 86 | 7% | Go |
| December | 29.0 | 84 | 0% | Go |
Verdict combines mean daytime high with rainy-day frequency. “Rainy days” is the share of days in the month with at least 1 mm of rain.
February is the driest month, with rain on 0% of days and daytime highs near 32.4°C (90°F). August is the wettest, at 98%. The warmest month is April at 36.7°C (98°F); the coolest is August at 28.5°C (83°F). The record rules out too hot in Mar–May; too wet in Jun–Oct.