Weather Assessment for the period 16^th to 30^th September 2025.

By the end of September, a slight-dry to moderate-dry spell developed across various farmlands. From the 16^th to 30^th below-normal rainfall occurred at Piarco, mainly due to one extremely wet day (18^th) and two wet days (23^rd, 29^th) and four relatively wet days that resulted in a 15-day rainfall total of 75.4 mm. At Crown Point, five relatively wet days (20^th ,22^nd, 26-27^th and 29^th ) contributed to a 15-day rainfall total of 16.6 mm at Crown Point. The rainfall totals maps for the period 16^th to 30^th of September for Trinidad and Tobago are located below as figure 1 and figure 2.

Figure 1. Rainfall map of Trinidad showing measured rainfall totals for varying districts during the period 16^th to 30^th of September 2025.

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during the period 16^th to 30^th of September 2025.
 

Temperatures:

The nationwide trend of warm nights and very warm to hot days has continued through the second half of September, particularly in Trinidad. Piarco observed three hot days (maximum temperature at least 34.0 ⁰C) with a maximum daytime temperature 34.3 ⁰C (19-20^th) however, the night-time minimum temperatures ranged from 24.0 ⁰C to 25.2 ⁰C at Piarco. 

Crown Point, Tobago did not observe any hot days (maximum temperatures at least 33.0 ⁰C at Crown Point) however very warm days and nights continued. The maximum daytime temperature was 32.5 ⁰C (22^nd, 23^rd) and the minimum temperatures ranged from 25.0 ⁰C to 28.4 ⁰C at Crown Point. Factoring the relative humidity however these temperatures had a ‘real feel’ that was higher than the observed maximum temperature.

Agro-meteorological Forecast: 

Date	Weather			Temperature	Heat Index ‘Feels Like’	Day Moisture (Relative Humidity)	Wind
1	30% chance of rainfall	1-3 mm of rainfall is possible	Fair to partly cloudy, isolated thunderstorm	Hot  Max/Min Temperatures 34°C/24°C	Feels like 36°C-38°C	50-70%	East-northeast 11-30 km/h Gust 50 km/h
2	30% chance of rainfall	1-3 mm of rainfall is possible	Fair to partly cloudy, isolated thunderstorm	Hot Max/Min Temperatures 34°C/25°C	Feels like 36°C-38°C	50-70%	East 11-30 km/h Gust 50 km/h
3	30% chance of rainfall	3-6 mm of rainfall is possible	Fair to partly cloudy, isolated heavy shower / thunderstorm	Hot Max/Min Temperatures 34°C/25°C	Feels like 37°C-38°C	50-70%	East-southeast 11-30 km/h Gust 50 km/h
4	30% chance of rainfall	3-6 mm of rainfall is possible	Fair to partly cloudy, isolated heavy shower / thunderstorm	Hot Max/Min Temperatures 34°C/25°C	Feels like 38°C-38°C	50-73%	East-southeast 11-30 km/h Gust 50 km/h
5	40% chance of rainfall	3-6 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower / thunderstorm	Hot Max/Min Temperatures 34°C/25°C	Feels like 38°C-38°C	50-73%	East-southeast 11-30 km/h Gust 50 km/h
6	60% chance of rainfall	5-6 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy showe / thunderstorm	Very Warm Max/Min Temperatures 33°C/25°C	Feels like 37°C-37°C	52-74%	East-southeast 11-30 km/h Gust 50 km/h
7	70% chance of rainfall	5-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower / thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-40°C	60-74%	East-northeast 11-30 km/h Gust 50 km/h
8	70% chance of rainfall	5-10 mm of rainfall is possible	Partly to mostly cloudy, scattered heavy showers / isolated thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-41°C	65-80%	East-northeast 11-30 km/h Gust 50 km/h
9	70% chance of rainfall	5-13 mm of rainfall is possible	Partly to mostly cloudy, scattered heavy showers / isolated thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-43°C	70-90%	East-southeast 11-30 km/h Gust 50 km/h
10	70% chance of rainfall	5-13 mm of rainfall is possible	Partly to mostly cloudy, scattered heavy showers / isolated thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-46°C	75-90%	East-southeast 11-30 km/h Gust 50 km/h
11	70% chance of rainfall	5-13 mm of rainfall is possible	Partly to mostly cloudy, scattered heavy showers / isolated thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-46°C	75-90%	East-southeast 11-30 km/h Gust 50 km/h
12	70% chance of rainfall	5-12 mm of rainfall is possible	Partly to mostly cloudy, scattered heavy showers / isolated thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 39°C-46°C	75-90%	East-southeast 11-30 km/h Gust 50 km/h
13	70% chance of rainfall	5-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower / thunderstorm	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 39°C-46°C	75-90%	East-southeast 11-30 km/h Gust 50 km/h
14	60% chance of rainfall	4-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower / thunderstorm	Hot Max/Min Temperatures 34°C/24°C	Feels like 39°C-47°C	70-80%	East 11-30 km/h Gust 50 km/h
15	60% chance of rainfall	4-6 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower / thunderstorm	Hot  Max/Min Temperatures 34°C/24°C	Feels like 39°C-47°C	70-80%	East 11-30 km/h Gust 50 km/h

Trinidad Rainfall Forecast for the 15-Day period of October (1^st to 15^th) 2025.

 Figure 3.  Rainfall map of Trinidad showing expected mean rainfall totals for districts across Trinidad during the 15-day period (1^st to 15^th) October 2025 and percentage probability of occurrence.

Eastern and North-Eastern areas: Moderate chance (65%) of mean daily rainfall up to 6.5 mm.

South-Eastern areas: Moderate chance (65%) of mean daily rainfall up to 5.4 mm.

Southern areas: Moderate chance (65%) of mean daily rainfall up to 5.1 mm.

South-Western areas: Moderate chance (65%) of mean daily rainfall up to 5.1 mm.

Central, West-Central, and inland areas: Moderate chance (55%) of mean daily rainfall up to 5.1 mm.

Northern, North-Western areas: Moderate chance (55%) of mean daily rainfall up to 5.5 mm. 

Tobago Rainfall Forecast for the 15-Day period of October (1^st to 15^th) 2025.

Figure 4.    Rainfall map of Tobago showing expected mean rainfall totals for districts across Tobago during the 15-day period (1^st to 15^th) October 2025 and percentage probability of occurrence.

North-Eastern areas: Moderate chance (65%) of mean daily rainfall up to 6.1 mm.

South-Western areas: Moderate chance (55%) of mean daily rainfall up to 4.5 mm.

Trinidad and Tobago:

During the 15-days, there is a moderate (55-65%) chance for near-to or below-normal rainfall. The 15-day period forecast rainfall totals in Trinidad are expected to range between 66 mm and 121 mm favoring northeastern hillsides of Trinidad, see figure 3. In Tobago, 15-day forecast rainfall is expected to range between 59 mm and 102 mm favouring farmlands in northern areas: Hillsborough, Main Ridge, see figure 4. There will be a moderate to high (70%) chance of slight-dry to moderate-dry conditions across most farmlands during the period. 

Temperatures & Winds:

Heat buildup is expected to increase, with a moderate to high heat hazard risk during the first week (1^st-6^th ) then lowering to moderate heat hazard risk by mid-October. There is a high (70%) chance of at least three hot days in a row due to a combined high (80%) chance of warmer than average nighttime temperatures and a high (70%) chance of above normal daytime temperatures. Temperatures are expected to feel as hot as 37°C to 45°C when factoring humidity on the hottest days when daily maximum temperatures of 32-34 °C are forecast. Warm nights with minimum temperatures of 24-27°C are expected (especially for southwestern Tobago and western Trinidad).

Generally, light to moderate southeasterly winds (near-to or below average wind speeds) are expected, however, there is a moderate to high (70%) chance of occasional gusts of 50 km/h or higher near heavy showers or isolated thunderstorms. Evaporation rates up to 5.0 mm per day on average are expected especially on hot days forecast during the period. 

Moisture levels:

Moderate to high moisture levels are expected across Trinidad and Tobago over the fifteen-day period, with average daytime relative humidity values expected from the low-50s to high-80s, in terms of percentage.

Highlighted Possible Impacts on Agriculture:

During the 15-days, a moderate risk of heat hazards during October remains for farm workers, young livestock, newly germinated and transplanted seedlings onto fields. The slight-dry to moderate-dry combined with very warm/hot conditions and slower wind speeds will maintain a moderate to high risk of pests/disease and a moderate risk of heat hazards nationwide. There is a moderate to high (70%) chance for fungal spread, insect pests and warm/moist weather diseases to develop in crop beds. 

Heavy showers will bring a moderate to high risk of street/flash flooding, overfilling ponds, land slippage on fields and access roads. 

Downpours/thunderstorms producing strong gusts will likely damage young plants and flowering mature plants in exposed hilly areas. 

So, continue to monitor streams and nearby watercourse levels. Implement pest and disease control measures as recommended. Monitor crops and animals for signs of heat stress and irrigate crops as needed especially in the flowering stage.

Sun and Moon Positions in the Sky October (1^st to 15^th) 2025.

The sun is presently at latitude 3.5 degrees South of the Equator. The day-length or number of sunlight hours in Trinidad and Tobago from October 1^st will be 12 hours, 1 minute decreasing to 11 hours, 53 minutes on October 15^th.

Moon Phases: Full Moon, 6^th and Third Quarter,13^th. According to the tradition of moon phases: October 3^rd – 5^th is a good day for planting above-ground crops; 8^th – 9^th and 12^th – 13^th are good days for planting below-ground crops; the remaining days are poor planting days and useful for removing weeds, clearing land and ploughing fields.