Jamaica Drought Monitor

Drought across Jamaica, parish by parish.

Island-wide summary

Jamaica at a glance

Rain over three months was below usual levels.

Latest month’s rainfall
36% less rain

Sept 2026

125 mm compared with 195 mm usual.

Rain over three months
52% less rain

Ending Sept 2026

239 mm compared with 497 mm usual.

Daytime heat
1.8°C warmer

Aug 2026

Average daytime high: 31.2°C; usual: 29.4°C.

Rainfall drought signal
Severely dry

Three months ending Sept 2026

How unusually dry or wet the season has been, based on rainfall.

CHIRPS rainfall

How recent rain compares with normal

Jamaica-wide estimated rainfall, compared with the same calendar periods in 1991–2020.

Today & tomorrow (projections)

GEFS outlook

Today

Fri, 23 Oct

365%

above normal rainfall

12 mm expected3 mm normal73% chance of rain

Tomorrow

Sat, 24 Oct

224%

above normal rainfall

8 mm expected3 mm normal75% chance of rain

Calibrated GEFS outlook, Jamaica-wide means · normal: CHIRPS 1991–2020 · generated 21 Oct 2026, 7:59 am

Last month

Sept 2026

36%

below normal rainfall

125 mm observed195 mm normal

Last 3 months

Ending Sept 2026

52%

below normal rainfall

239 mm observed497 mm normal

Last 6 months

Ending Sept 2026

34%

below normal rainfall

648 mm observed989 mm normal

Last 12 months

Ending Sept 2026

1%

above normal rainfall

1,736 mm observed1,727 mm normal

Nearby storms
  • Melissa · Oct 2025

Standardized Precipitation Index

How unusual is the rainfall?

Jamaica-wide · SPI-3−1.69Severe drought

Rainfall window
Jul 2026–Sept 2026

Calibration: 1991–2020
Same 3-month window and ending calendar month.

239 mm accumulated rainfall · 30 complete calibration years.

Extreme drought · ≤ −20 · normalExtremely wet · ≥ +2

Below zero: below normal rainfall. Above zero: above normal rainfall.

SPI describes rainfall conditions. It is a derived meteorological drought indicator, not an official Jamaica Met Service declaration.

Scale and calculation

Rainfall is added over 3 complete months. A gamma distribution fitted to matching 1991–2020 rainfall windows converts the total into a standardized, unitless index. Values are classified before rounding.

SPI scale with the near-normal range split at zero · WMO SPI guide
BandSPI value
Extreme droughtSPI ≤ −2
Severe drought−2 < SPI ≤ −1.5
Moderate drought−1.5 < SPI ≤ −1
Below normal−1 < SPI < 0
NormalSPI = 0
Above normal0 < SPI < +1
Moderately wet+1 ≤ SPI < +1.5
Very wet+1.5 ≤ SPI < +2
Extremely wetSPI ≥ +2

The dry bands correspond to WMO moderately dry, severely dry and extremely dry. Missing rainfall windows, fewer than 30 calibration years, or failed fit checks withhold the index.

The WMO near-normal range (−1 to +1, excluding the ends) is divided into below normal, exactly normal and above normal here. The drought and wet thresholds are unchanged.

The gauge spans −3 to +3; values outside that display range sit at its ends. The numeric value retains its calculated magnitude.

Input history: Jan 1981–Sept 2026. Calibration remains fixed at 1991–2020.

Derived SPI · Rainfall source: CHIRPS v3 monthly · WMO classification. Calculated .

Temperature / Heat

How warm was the latest month?

Jamaica-wide · Aug 2026
Daily temperature extremes averaged over the month.

Average daytime high above normal+1.8°CCompared with 1991–2020 for the same calendar month.
Average daytime high
31.2°C
1991–2020 normal: 29.4°C
Average nighttime low
25.4°C
1991–2020 normal: 23.8°C