Ayiti, klima ak metyo mansyèl, oktòb 2025

FAMINE EARLY WARNING SYSTEMS NETWORK Haiti Monthly Climate and Weather 20 November 2025 Highlights • La Niña conditions continued over the past month, as indicated by the strengthening of below-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific Ocean. According to the NOAA ENSO Diagnostic Discussion, La Niña is favored to continue into the Northern Hemisphere winter, with a transition to ENSO-neutral most likely in January-March 2026 (61% chance). Historically, El Niño is associated with drier than average conditions and La Niña with wetter than average conditions in Haiti. • October is the third month of the second rainy season in Haiti. Climatological rainfall typically peaks or remains high during this month, generally ranging from 40 mm to 350 mm across Haiti, with the highest totals often found in the southern and western regions. • During October 2025, Haiti’s Grand’Anse, Nippes, and Sud departments observed highest rainfall values between 300 mm to 500 mm. These extreme totals were driven by Hurricane Melissa. According to the FEWS NET, the flooding associated with Hurricane Melissaled to affected several municipalities, including Corail (whose city center was submerged) and Anse-d’Hainault and the Cayemites Islands (affected by coastal flooding). Dozens of makeshift dwellings in Beaumont and Pestel were damaged. Ten of eleven municipalities in Nippes experienced flooding and material damage. • The NMME seasonal forecast for December 2025 – February 2026 suggests enhanced probabilities exceeding 36% for above normal over southern Haiti, while forecast probabilities for rainfall are normal in most parts of western Haiti. • The SPI forecast anticipates above-average conditions in northwestern and southwestern Haiti, while predicting below-average conditions across eastern Haiti. The FEWS NET Monthly Climate and Weather information bulletin is based on current weather and climate information and monthly and seasonal outlooks from the NOAA CPC. Information on crops, soil moisture, flooding, and evapotranspiration data were produced by FEWS NET, USGS, NASA and USDA. Various sources were used to assess impacts of extreme conditions. Questions or comments about this product may be directed to Dr. Wassila Thiaw, Deputy Director, CPC/NOAA, wassila.thiaw@noaa.gov. Questions about the DOS FEWS NET may be directed to Dr. Kiersten Johnson, Program Manager FEWS NET/DOS, johnsonkb2@state.gov. Haiti seasonal calendar. Source: FEWS NET Current Climate Modes and Teleconnections • During the last 4 weeks, equatorial SSTs were below average across the central and eastcentral Pacific Ocean. SSTs were above average in the western Pacific Ocean. • The ENSO outlooks predict La Niña conditions are favored to persist through December 2025 - February 2026, with a transition to ENSO-neutral likely in January-March 2026 (55% chance; Fig. 1). For the latest update from the NOAA Climate Prediction Center (CPC) on ENSO, check here. • Much of the Caribbean Sea experienced little to no change in SST anomalies. Figure 1. Official ENSO probabilities for the Niño 3.4 SST index (5oN−5oS, 120oW−170oW). Figure updated 9 October 2025. Source: NOAA/CPC • Implications of ENSO conditions: Based on historical records, La Niña conditions are associated with above average precipitation throughout Haiti for November to January season (Fig. A1, left panels). La Niña conditions are also related to below average mean 2 temperatures in Haiti (Fig. A1, right panels). The ENSO-precipitation teleconnection pattern can be found here, and the pattern for temperature can be found here. Extreme Events • Haiti experienced the impacts of hurricane/tropical storm Melissa in the last few days of October 2025, with alerts issued as early as the 21st and the most severe impacts occurring around October 28-29. (U.S. Embassy in Haiti) • Casualties and displacement: As of early November 2025, the storm had resulted in at least 43 deaths, 21 injuries, and 13 missing persons in Haiti. Over 11,900 houses were flooded, and around 16,000 people sought refuge in temporary shelters. (OCHA, 12 November 2025) • Infrastructure damage: Road infrastructure was severely damaged, particularly in the southern departments, hampering humanitarian aid delivery. (OCHA, 12 November 2025) • There have been no reports of fire activity in Haiti during October 2025. Rainfall/Precipitation • October is the third month of the second rainy season in Haiti. Climatological rainfall typically peaks or remains high during this month, generally ranging from 40 mm to 350 mm across Haiti, with the highest totals often found in the southern and western regions. While the country generally sees significant rain, the passage of Hurricane Melissa led to extreme localized rainfall and major flooding. Past 3 months (August – October 2025): • Totals: Over the last three months, the largest amounts of total rainfall ranged from 300 mm to 500 mm in southwestern Haiti and Gonave island. The southern parts of Sud department of Haiti’s experienced the highest total rainfall over 750 mm. The Port-de-Paix, Nord, Artibonite, Centre and western Ouest department of Haiti’s experienced moderate rainfall, with totals of 100 mm to 300 mm. The Nord-Est, eastern parts of Ouest, and eastern Sud-Est received comparatively lower amounts of rainfall, ranging from 50 mm to 100 mm. • Anomalies: During the last three months, Haiti experienced below average conditions over most of the eastern Haiti, whereas few parts of southwestern Haiti experienced above average conditions. Parts of Centre department registered the highest rainfall deficits ranging from 300 mm to 500 mm, while the rest of Haiti registered below average amounts from 25 mm to 200 mm. Past 1 Month (October 2025): • Totals: During the past month, Haiti’s Grand’Anse, Nippes, and Sud departments observed highest rainfall values between 300 mm to 500 mm. The Port-de-Paix, Gonave Island, eastern parts of Nippe, and western parts of Ouest department of Haiti’s experienced moderate rainfall, with totals of 100 mm to 300 mm. The Nord, Artibonite, Centre and western Ouest Nord-Est, eastern parts of Ouest, and eastern Sud-Est received comparatively lower amounts of rainfall, ranging from 25 mm to 100 mm (Fig. 2a). 3 • Anomalies: During October, drier than average conditions continued over eastern and central Haiti, whereas Nord-Ouest, southwestern Haiti and Gonave Island experienced above average conditions. Centre, southern Nord-Est departments registered the highest rainfall deficits ranging from 50 mm to 100 mm, while the rest of eastern and central Haiti registered above average conditions from 25 mm to 50 mm (Fig. 2b). a) b) c) Figure 2. Satellite estimates of precipitation (CMORPH) for October 2025: (a) 1-month total accumulation and (b) 1-month anomaly. (c) NMME seasonal rainfall probabilistic forecast for December 2025 – February 2026. Source: NOAA/NCEP Monthly and Seasonal Forecasts (December 2025 and December 2025 – February 2026): • Monthly: The North American Multi-Model Ensemble (NMME) models do not show strong predictive signals across most parts of Haiti for December 2025. Weak probabilities (36-40%) for above-average rainfall are indicated in western Sud (not shown). • Seasonal: The NMME seasonal forecast for December 2025 – January 2026 suggests that the probability of above-average rainfall exceeds 40% over eastern Sud-Est and hover between 36-40% in Sud departments of Haiti. No dominant category is predicted for the rest of the country (Fig. 2c). Temperature Past 3 months (August – October 2025): • Maximums: Haiti experienced maximum temperatures ranging from 25°C to 35°C. The Nord-Ouest department, and central parts of southern Haiti experienced slightly above average anomalies between 1°C and 2°C, while the rest of Haiti observed near average temperature anomalies. • Minimums: Most of Haiti recorded minimums between 20°C and 25°C. Cooler temperatures of 15°C to 20°C were observed in southeastern Haiti while warmer temperatures of 20 °C to 25 °C were recorded in southern, central and northern Haiti. Near average minimum temperature anomalies prevailed in Haiti during these three months. 4 Past 1 Month (October 2025): • Maximums: Monthly maximum temperatures across Haiti ranged from 25°C to 35°C. Near-average anomalies were observed in Haiti during the month of October (Fig. 3a). • Minimums: Most of Haiti recorded minimum temperatures between 20°C and 25°C, while cooler minimums (15°C to 20°C) were observed in isolated southeastern areas. Compared to the long-term climate, the observed values were within ±1oC of the average across Haiti (Fig. 3b). b) c) a) Figure 3. Spatial structure of temperature for September 2025. (a) Maximum temperature anomaly and (b) minimum temperature anomaly. (c) NMME probabilistic forecast of seasonal 2m temperature for November 2025 – January 2026. Source: NOAA/NCEP Monthly and Seasonal Forecasts (December 2025 and December 2025 – February 2026): • Monthly: The NMME forecast for December indicates an increased likelihood (over 60%) of above-average temperatures in northern, north-eastern, and southern Haiti. There is no clear signal for near-, above-, or below-average temperatures in the central-east regions. • Seasonal: For the December 2025 – February 2026 season, there is an increased likelihood (over 60%) of above average temperatures in northern, north-eastern, and southern regions of Haiti. The forecast indicates no clear signal for near-, above-, or belowaverage temperatures in the central-east regions of the country (Fig. 3c). Drought and Dryness The Standardized Precipitation Index (SPI) is used to characterize meteorological drought. SPI compares the precipitation over a specific period of time with the climatology from that same period. Therefore, the SPI values can be thought of as the number of standard deviations the observed anomaly deviates from the climatology. The 1-month SPI values are a good representation of the monthly precipitation anomaly as well as the soil moisture and vegetation health. The 3-month SPI values are a good representation of seasonal precipitation anomalies. The Standardized Precipitation Evapotranspiration Index (SPEI) is similar to the SPI, but it also takes evapotranspiration into account (and therefore the impact of temperatures on water demand). 5 Past 3 Months (August – October 2025): • The SPI analysis for the past 3 months indicated that drier than average conditions (SPI values of 0.8 to more than 1.6 standard deviations below the mean) dominated over the central and eastern regions of Haiti. The lowest SPI values (more than 1.3 standard deviations below the mean) were in Nord-Est and Centre departments. The southern parts of Haiti experienced wetter than average conditions (SPI values of 0.5 to more than 1.6 standard deviations above the mean). Past 1 Month (September 2025): • The SPI analysis for October 2025 indicated that Haiti experienced drier than average conditions (SPI values of 0.8 to 1.3 standard deviations below the mean) over the central and eastern regions. The northern and southern parts of Haiti experienced wetter than average conditions (SPI values of 0.5 to more than 1.6 standard deviations above the mean). Current/Forecast (31 August 2025 to 28 November 2025): • The SPI forecast suggests drier than average conditions (SPI values of 0.5 to 1.3 standard deviations below the mean) over the central and eastern regions of Haiti. However, SPI forecast seems to indicate wetter-than-average conditions (SPI values ranging from 0.5 to 1.6 standard deviations above the mean) in northwestern and southwestern parts of Haiti. Water Requirement Satisfaction Index (WRSI) • N/A GEOGLAM Crop Monitor • GEOGLAM Crop Monitor synthesis indicated that ‘favorable’ conditions in Haiti for maize and rice during October 2025. Additional Resources - https://protectioncivile.gouv.ht/ - https://www.meteo-haiti.gouv.ht/ 6 Annex Figure A1. ENSO teleconnection for the November-December-January (NDJ) season. The upper-level panel shows the precipitation and temperature anomalies regressed onto the standardized Niño-3.4 index. The bottom panel shows the correlation between Nino-3.4 and the anomalies. Source : https://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/regressions/ 7