September weather forecast
French Guiana

September in French Guiana marks a transition period as the country begins to move from the lesser rainy season back towards the greater rainy season. In Cayenne, the coastal capital, the average rainfall is about 100mm (3.94"), maintaining similar levels as in August. However, the number of rainy days begins to increase marginally, signalling the impending arrival of the greater rainy season.

Similarly, inland areas such as Saint-Laurent-du-Maroni exhibit a stable level of rainfall in September but with an upward trend towards the end of the month. The subtle changes in precipitation patterns reflect the gradual shift in seasons throughout the country.

Despite these subtle shifts in rainfall, temperatures in September continue to remain consistent, as observed throughout the year. Nighttime temperatures hover around a low of 23°C (73.4°F), while daytime temperatures can reach up to 31°C (87.8°F). The transition towards the greater rainy season does not significantly affect these temperatures, further demonstrating the stability of French Guiana's tropical climate.

Sunlight in September is relatively steady, with coastal areas receiving about 7 hours of sunshine per day. The frequency of overcast days slightly increases as the month progresses, indicative of the increasing cloud cover associated with the imminent rainy season.

Visitors to French Guiana in September should expect stable rainfall and temperature conditions, with a slow increase in precipitation towards the end of the month. While humidity remains high, the stable conditions early in the month could provide ample opportunity for outdoor activities before the onset of the greater rainy season.

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• Cayenne - September »
  September is the month with the least rainfall in Cayenne, French Guiana. September in Cayenne is synonymous with the driest month.
• Kourou - September »
  The month with the least rainfall in Kourou is September, when the rain falls for 4.4 days and typically collects 33mm (1.3") of precipitation. On the first day of September in Kourou sunrise is at 06:24 and sunset at 18:36.
• Remire-Montjoly - September »
  In Remire-Montjoly in September, the average water temperature is 28.5°C (83.3°F). In September, the average sea temperature in Remire-Montjoly is 28.5°C (83.3°F).
• Maripasoula - September »
  On the first day of September in Maripasoula sunrise is at 06:30 and sunset at 18:41. In Maripasoula the average relative humidity in September is 74%.
• Mana - September »
  Peak heat is expected in Mana in September, with temperatures soaring to a high of 32.7°C (90.9°F)—the hottest month of the year. In Mana, French Guiana, in September, the average water temperature is 28.2°C (82.8°F).
• Apatou - September »
  On the last day of September, in Apatou, French Guiana, sunrise is at 06:24 and sunset at 18:29 -03. In Apatou the average relative humidity in September is 79%.
• Grand-Santi - September »
  The month with the most sunshine in Grand-Santi is September, with an average of 9.1h of sunshine. The weather conditions in Grand-Santi during September record significant changes with the reduction in humidity levels and the steady decrease of rainfall.
• Camopi - September »
  Handing over the reins from August to September in Camopi the weather sees a substantial ascent in temperature, with the mercury soaring up to 33.7°C (92.7°F). In Camopi during September, the rain falls for 12.5 days and regularly aggregates up to 21mm (0.83") of precipitation.
• Iracoubo - September »
  The month with the least rainfall in Iracoubo is September, when the rain falls for 14.3 days and typically collects 29mm (1.14") of precipitation. The months with the lowest humidity in Iracoubo are September and October, with an average relative humidity of 77%.
• Saul - September »
  In Saul in September, during 14.3 rainfall days, 36mm (1.42") of precipitation is typically accumulated. On the first day of September in Saul, French Guiana, sunrise is at 06:27 and sunset at 18:38.