Guanacaste
September
Weather in Guanacaste for September 2026
Your guide to Guanacaste weather in September - trends and predictions
So far, September 2026 in Guanacaste shows a warmer trend than usual by 4 °C.
The forecast for the next days in Guanacaste predicts temperatures to be around 31 °C, close to the historical average.
In general, the average temperature in Guanacaste at the beginning of September is 31.1 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 28 °C by the end of September.
Guanacaste experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 451.2 mm.
Temperatures
Rain 🌧️
0
Dry days
30
Rainy days
0
Snow days
28°/22°
Temperatures
10 km/h
Avg max wind
86 %
Avg humidity
Guanacaste Weather September
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Temperatures trend during September in Guanacaste
See the weather trend as well as the moving average line
September weather in Guanacaste day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Moderate or heavy rain shower | 32° /23° | 7.6 mm | 5 | |
| 2 Sept. | Moderate or heavy rain shower | 32° /22° | 14.8 mm | 6 | |
| 3 Sept. | Moderate or heavy rain shower | 31° /23° | 10.6 mm | 6 | |
| 4 Sept. | Moderate or heavy rain shower | 32° /23° | 5.7 mm | 8 | |
| 5 Sept. | Moderate or heavy rain shower | 31° /23° | 9.1 mm | 5 | |
| 6 Sept. | Moderate or heavy rain shower | 30° /23° | 9.4 mm | 5 | |
| 7 Sept. | Moderate or heavy rain shower | 30° /22° | 34.6 mm | 5 | |
| 8 Sept. | Moderate or heavy rain shower | 30° /22° | 11.5 mm | 7 | |
| 9 Sept. |  Patchy rain possible | 31° /23° | 9 mm | 8 | |
| 10 Sept. |  Heavy rain at times | 32° /23° | 6 mm | 5 | |
| 11 Sept. | Moderate or heavy rain shower | 32° /23° | 8.7 mm | 5 | |
| 12 Sept. | Moderate or heavy rain shower | 32° /23° | 5.8 mm | 8 | |
| 13 Sept. | Moderate or heavy rain shower | 31° /22° | 22.7 mm | 5 | |
| 14 Sept. | Moderate or heavy rain shower | 31° /23° | 8.8 mm | 5 | |
| 15 Sept. | Moderate or heavy rain shower | 30° /23° | 12.4 mm | 5 | |
| 16 Sept. |  Overcast | 35° /24° | 0 mm | 11.5 | |
| 17 Sept. | Overcast | 37° /24° | 0.1 mm | 10.9 | |
| 18 Sept. | Overcast | 35° /24° | 0.3 mm | 11.2 | |
| 19 Sept. |  Sunny | 37° /24° | 2.1 mm | 10.5 | |
| 20 Sept. | Light rain shower | 36° /24° | 9.7 mm | 8 | |
| 21 Sept. | Light rain shower | 29° /23° | 13 mm | 6 | |
| 22 Sept. | Light rain shower | 25° /23° | 14.9 mm | 5 | |
| 23 Sept. | Light rain shower | 29° /23° | 14 mm | 6 | |
| 24 Sept. | Light rain shower | 31° /23° | 21.2 mm | 7 | |
| 25 Sept. |  Mist | 27° /22° | 81.3 mm | 6 | |
| 26 Sept. | Overcast | 26° /22° | 13.9 mm | 6 | |
| 27 Sept. | Overcast | 28° /23° | 6.5 mm | 6 | |
| 28 Sept. | Overcast | 28° /23° | 4.2 mm | 6 | |
| 29 Sept. | Light rain shower | 28° /23° | 18.9 mm | 6 | |
| 30 Sept. | Light rain shower | 28° /22° | 16.8 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for Guanacaste in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Guanacaste forecast closer to your planned date for the most up-to-date weather information.
Change Month
Guanacaste in September - FAQ
What are the expected maximum and minimum temperatures in Guanacaste during September?
During September, expect a variety of temperatures with highs around 28° and lows near 22°, suitable for diverse activities and preferences.
How much rainfall should be expected in Guanacaste during September?
Significant rainfall exceeding 451.2 mm is expected in Guanacaste during September, occurring over more than 30 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Guanacaste during September?
The average wind speed in Guanacaste during September is 10 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Guanacaste
Explore the daily rainfall trends and prepare for Guanacastes September weather 💧
Typically, Guanacaste has 30 rainy days in September with a total of 451.2 mm of rainfall.
UV exposure in Guanacaste during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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