🌧️ Unveiling "WAF": 2026 Thailand Rainfall Outlook | How to Prepare? The results are in! We are looking at the 2026 monthly rainfall forecast maps from the WAF (Weather and Climate Forecasting) model by the Hydro-Informatics Institute (HII). This bird's-eye view of the year is essential for farmers
🌧️ Unveiling "WAF": 2026 Thailand Rainfall Outlook | How to Prepare?
The results are in! We are looking at the 2026 monthly rainfall forecast maps from the WAF (Weather and Climate Forecasting) model by the Hydro-Informatics Institute (HII). This bird's-eye view of the year is essential for farmers and water management authorities to plan ahead.
📊 Overall Summary: A Wet or Dry Year?
Data suggests that 2026 will see early and heavy rainfall, particularly from mid-year through the end of the year. Key trends to watch:
🔍 Quarterly Deep Dive
1. Q1 (Jan - Mar): "The Dry Spell Preparation"
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Rainfall remains low according to the season. February (17 mm) is projected to be the driest month of the year.
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Most of the country is highlighted in white and yellow (low rainfall). It is crucial to conserve and store water for agricultural use during this period.
2. Q2 (Apr - Jun): "Early & Intense Monsoon"
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April (98 mm): Rain signals begin to appear, particularly in the South and East.
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May (223 mm): The first peak! Heavy rain will cover most of the country (indicated by blue and pink zones), signaling the official start of the rainy season.
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June (139 mm): A slight "rain break" compared to May, though steady precipitation continues.
3. Q3 (Jul - Sep): "Maximum Flood Watch"
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Rainfall climbs steadily from 181 mm in July to 272 mm in September.
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September: This is the heaviest rainfall month of the year. Large areas are marked in deep purple and red (>300 mm), posing a significant risk of flash floods and forest runoffs.
4. Q4 (Oct - Dec): "Rain Shifts South"
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Rainfall in the North and Northeast begins to subside as the cold season arrives.
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However, the Southern region remains in the "deep purple" zone (especially Nov - Dec) due to the influence of the Northeast Monsoon.
💡 Recommendations & Preparation
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For Farmers: Be vigilant about flooding in crop areas during May and between August–September. For the start of the year, ensure your water reservoirs are managed efficiently to survive the dry months.
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Water Management: Local authorities should prioritize clearing drainage systems and canals before the heavy rains arrive in May.
Note: This is a long-term model projection. Actual weather conditions may vary due to additional factors like tropical cyclones.