Summary of Expected conditions:

Near to above normal rainfall is expected 16^th - 31^st May. Wet days are forecast 17^th  - 21^st and 25^th - 27^th with forecast daily rainfall totals up to 20 mm expected to cause street/flash flooding on access roads, saturated soils and overfill ponds across most farmlands. For the remainder of the period, relatively wet days and very warm conditions are expected to bring a moderate risk of disease as well as heat stress during the fifteen days.

Weather Assessment for the period 1^st to 15^th May, 2025.

The waning of the dry season brought total rainfall closer to the May average in Tobago. During the period, four wet days contributed to the 15-day rainfall total of 71.1 mm at Crown Point. In Trinidad, two wet days contributed to the 15-day rainfall total of 42.3 mm at Piarco, though higher in eastern Trinidad.  

The rainfall totals maps for the period 1^st to 15^th of May 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 1^st to 15^th of May.

Figure 2. Rainfall map of Tobago showing measured rainfall totals for varying districts during the period 1^st to 15^th of May.
 

Temperatures:

Warm conditions dominated the period, accelerating crop development but also maintaining the moderate risk of heat stress, especially in wind-sheltered areas. Warm to very warm nights dominated the period with one hot day 34.3 ⁰C(12^th) observed at Piarco (maximum temperature over 34.0 ⁰C), The minimum night-time temperatures ranged from 23.4 ⁰C to 25.4 ⁰C at Piarco. Tobago experienced very warm night-time conditions but no hot days (maximum temperatures above 33.0 ⁰C at Crown Point). The maximum daytime temperature was 31.9 ⁰C (1^st) and the minimum night-time temperatures ranged from 24.6 ⁰C to 27.2 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 ‘RealFeel’	Day Moisture (Relative Humidity)	Wind
16	60% chance of rainfall	3-6 mm of rainfall is possible	Partly to mostly cloudy, hazy, breezy, isolated heavy shower/ thunderstorm	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-80%	East-southeast 20-39 km/h Gust 50 km/h
17	70% chance of rainfall	8-15 mm of rainfall is possible	Mostly cloudy, rain, few heavy showers/ thunderstorms	Warm Max/Min Temperatures 31°C/24°C	Feels like 34°C-36°C	65-80%	East-southeast 20-30 km/h Gust 50 km/h
18	80% chance of rainfall	8-20 mm of rainfall is possible	Cloudy to overcast, rain, heavy showers/ thunderstorms	Warm Max/Min Temperatures 30°C/23°C	Feels like 32°C-34°C	65-80%	Southeast 20-30 km/h Gust 50 km/h
19	80% chance of rainfall	8-20 mm of rainfall is possible	Cloudy to overcast, rain, heavy showers/ thunderstorms	Warm Max/Min Temperatures 30°C/23°C	Feels like 32°C-34°C	65-80%	Southeast 20-30 km/h Gust 50 km/h
20	70% chance of rainfall	8-15 mm of rainfall is possible	Mostly cloudy to cloudy, heavy showers/thunderstorms	Warm Max/Min Temperatures 31°C/24°C	Feels like 34°C-36°C	65-80%	Southeast 20-30 km/h Gust 50 km/h
21	70% chance of rainfall	8-15 mm of rainfall is possible	Mostly cloudy to cloudy, few heavy showers/thunderstorms	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-80%	Southeast 20-30 km/h Gust 50 km/h
22	60% chance of rainfall	3-5 mm of rainfall is possible	Partly to mostly cloudy, showers	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-80%	East-southeast 20-39 km/h Gust 50 km/h
23	60% chance of rainfall	3-5 mm of rainfall is possible	Partly to mostly cloudy, showers	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-75%	East 20-39 km/h Gust 50 km/h
24	60% chance of rainfall	3-5 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower/thunderstorm	Warm Max/Min Temperatures 32°C/25°C	Feels like 36°C-38°C	60-70%	East-northeast 20-39 km/h Gust 50 km/h
25	60% chance of rainfall	6-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower/thunderstorm	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-75%	East-northeast 20-39 km/h Gust 50 km/h
26	60% chance of rainfall	6-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower/ thunderstorm	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-75%	East-southeast 20-30 km/h Gust 50 km/h
27	60% chance of rainfall	6-10 mm of rainfall is possible	Partly to mostly cloudy, isolated heavy shower/ thunderstorm	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-75%	East-southeast 20-30 km/h Gust 50 km/h
28	70% chance of rainfall	3-5 mm of rainfall is possible	Partly to mostly cloudy, showers	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-41°C	65-80%	East 20-30 km/h Gust 50 km/h
29	70% chance of rainfall	3-5 mm of rainfall is possible	Partly to mostly cloudy, showers	Very Warm Max/Min Temperatures 33°C/24°C	Feels like 38°C-41°C	65-80%	East 20-39 km/h Gust 50 km/h
30	70% chance of rainfall	3-4 mm of rainfall is possible	Partly to mostly cloudy, showers	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-80%	East-southeast 20-39 km/h Gust 50 km/h
31	70% chance of rainfall	3-4 mm of rainfall is possible	Partly to mostly cloudy, showers	Warm Max/Min Temperatures 32°C/24°C	Feels like 36°C-39°C	65-80%	East-southeast 20-39 km/h Gust 50 km/h

Trinidad Rainfall Forecast for the 15-Day period of May (16^th to 31^st) 2025.

Figure 1.  Rainfall map of Trinidad showing expected mean rainfall totals for districts across Trinidad during the 15-day period (16^th to 31^st) May 2025 and percentage probability of occurrence.

Eastern and North-Eastern areas: Moderate chance (55%) of mean daily rainfall up to 9.6 mm.

South-Eastern areas:  High chance (75%) of mean daily rainfall up to 10.3 mm.

Southern areas: High chance (75%) of mean daily rainfall up to 9.7 mm.

South-Western areas: High chance (75%) of mean daily rainfall up to 9.6 mm.

Central, West-Central, and inland areas: Moderate chance (65%) of mean daily rainfall up to 8.4 mm.

Northern, North-Western areas: Moderate chance (65%) of mean daily rainfall up to 7.6 mm. 

Tobago Rainfall Forecast for the 15-Day period of May (16^th to 31^st) 2025.

Figure 2.    Rainfall map of Tobago showing expected mean rainfall totals for districts across Tobago during the 15-day period (16^th to 31^st) May 2025 and percentage probability of occurrence.

North-Eastern areas: Moderate chance (60%) of mean daily rainfall up to 6.4 mm.

South-Western areas: Moderate chance (60%) of mean daily rainfall up to 5.9 mm.

Trinidad and Tobago:

From May 16^th - 31^st, slower wind speeds combined with equatorial moisture moving over the Guianas towards Trinidad and Tobago will encourage the build up of rain-bearing clouds and favour heavy rainfall during the period. For the 15-days, mostly cloudy to cloudy conditions will be interrupted by moderate showers (70% chance) with periods of light to moderate rain, alongside a moderate chance (40%) of heavy showers  and thunderstorms with gusty winds favoring areas of southern, eastern Trinidad and eastern Tobago, which may result in flooding of access roads and low-lying fields. 

The 15-day period forecast rainfall totals in Trinidad are expected to range between 92 mm and 154 mm across most farmlands, though isolated higher amounts are possible for southern and northeastern Trinidad. In Tobago, 15-day forecast rainfall is expected to range between 82 mm and 100 mm favoring southern areas of Tobago such as Patience Hill, Mason Hall and Goodwood.

Temperatures & Winds:

The heat season continues and there is a moderate (60%) chance of warmer than average temperatures nationwide, particularly during nighttime. During the 15-days there is a moderate (40%) chance of a 2-day hot spell, favouring western Trinidad. Forecast daily maximum temperatures will range from 29-32 °C in Tobago and 29-33 °C in Trinidad. So when factoring humidity on the warmest days, temperatures are expected to feel as hot as 32-41°C on most days. Minimum temperatures of 23-25°C are expected during most nights/early mornings, though warmer near western areas and coastlines.

Less breezy conditions are expected with mainly moderate easterly winds. However gusts of 50 km/h or higher are possible near heavy showers or isolated thunderstorms. Combined with above normal temperatures, evapotranspiration rates in crops of 3.0 mm to 7.0 mm per day are expected.

Moisture levels:

Moderate moisture levels are expected across Trinidad and Tobago over the fifteen-day period, with average daytime relative humidity values mainly ranging from the mid-60s to high-80s, in terms of percentage.

Highlighted Possible Impacts on Agriculture:

Bouts of heavy rainfall are likely to cause street/flash flooding on access roads, saturated soils and overfill ponds across most farmlands. There is a low concern for dryness across farmlands in western and northwestern areas of Trinidad, such as Carenage and Petit  Valley. Farmers should maintain scheduling of irrigation days on fields however to maintain optimal soil moisture where necessary. A moderate (65%) chance of heat stress exists for farm workers, young livestock, newly germinated and transplanted seedlings onto fields. There is a moderate (60%) chance that strong gusts may damage young plants and flowering mature plants in exposed hilly areas. There is a low (30%) chance for fungal spread, insect pests and warm/moist weather diseases to develop in crop beds.

Continue to monitor crops and animals for signs of heat stress, monitor streams and nearby watercourses  levels, soil moisture  and irrigate as needed, especially for crops in the flowering stage. Implement pest and disease control measures as recommended. Consider applying mulch to conserve soil moisture.

Sun and Moon Positions in the Sky May (16^th to 31^st) 2025.

The sun is presently overhead at latitude 19.3 degrees North of the Equator. The day-length or number of sunlight hours in Trinidad and Tobago on May 16^th will be 12 hours, 37 minutes increasing to 12 hours, 42 minutes on May 31^st.

Moon Phases: Third Quarter, 20^th; New Moon, 26^th. According to the tradition of moon phases: May 16^th, 20^th - 21^st ,24^th - 25^th are good days for planting below-ground crops ; 20^th  – 21^st , 28^th – 29^th are good days for planting vine and above-ground crops; the remaining days are poor planting days and useful for removing weeds, clearing land and ploughing fields.