Flood Intel Dashboard
Snapshot from 20 May 2026
📊 Historical Flood Pattern Analysis (30-Year Data)
2724
Avg Annual Rainfall (mm)
231
Max Daily Rainfall (mm)
88
Heavy Rain Days (>50mm)
8
Extreme Days (>100mm)
📈 How Climate Has Changed (30-Year Analysis)
Key Findings:
- •Extreme rainfall events (>100mm/day) have increased by 350%
- •Maximum daily rainfall intensity has increased by 14%
- •Extreme events in the last decade (5) are significantly higher than the first decade (1)
First Decade
1996-2005
Avg Rainfall2574 mm/yr
Extreme Days1
Max Daily202 mm
Second Decade
2006-2015
Avg Rainfall2717 mm/yr
Extreme Days2
Max Daily112 mm
Last Decade
2016-2026
Avg Rainfall2620 mm/yr
Extreme Days5
Max Daily231 mm
Change Over 30 Years (First vs Last Decade)
Annual Rainfall
2574 mm
2620 mm
+1.8%
Extreme Rain Days (>100mm)
0.1 days/yr
0.5 days/yr
+350.0%
Rainy Days per Year
269 days
260 days
-3.3%
Max Daily Intensity
202 mm
231 mm
+14.4%
Extreme Rainfall Events by Decade (>100mm/day)
1
1996-2005
2
2006-2015
5
2016-2026
400% increase in extreme events from first to last decade
5-Year Moving Average Trend
2000Recent trend highlighted2026
Radial Monthly Rainfall Pattern
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Colombo
30yr avg
HIGH Risk
MEDIUM Risk
LOW Risk
Monthly Flood Risk Profile
83
Jan
⚡
70
Feb
✓
105
Mar
✓
187
Apr
✓
300
May
⚠️
294
Jun
⚡
243
Jul
⚡
225
Aug
⚡
274
Sep
⚠️
367
Oct
⚠️
367
Nov
⚠️
186
Dec
✓
HIGH Risk
MEDIUM Risk
LOW Risk
Seasonal Rainfall Treemap
Southwest Monsoon (May-Sep)
4301 rainy days
Avg Daily
8.8mm
Max Day
231mm
Heavy Days
19
Extreme
2
Northeast Monsoon (Nov-Feb)
1830 rainy days
Avg Daily
5.8mm
Max Day
218mm
Heavy Days
40
Extreme
6
Inter-Monsoon (Mar-Apr, Oct)
2107 rainy days
Avg Daily
7.1mm
Max Day
95mm
Heavy Days
29
Extreme
0
Southwest Monsoon
Northeast Monsoon
Inter-Monsoon
Risk Gauge Indicators
0.3
Extreme Events/Year
2.9
Heavy Rain Days/Year
231
Max Daily (mm)
4
High Risk Months
Monthly Rainfall Range (Avg to Max)
Jan
83 / 109
Feb
70 / 60
Mar
105 / 81
Apr
187 / 68
May
300 / 231
Jun
294 / 51
Jul
243 / 52
Aug
225 / 49
Sep
274 / 202
Oct
367 / 95
Nov
367 / 218
Dec
186 / 70
Avg Rainfall
Max Range
Max Daily
30-Year Trend Sparklines
Annual Rainfall569mm
19962026
Extreme Days/Year0
19962026
Max Daily/Year42mm
19962026
Extreme Event Heatmap (by Month)
J
F
M
A
M
J
J
A
S
O
N
D
Events
1
1
1
5
0
Low
Med
High
Critical
Monsoon Season Analysis
Southwest Monsoon (May-Sep)
Avg Daily Rain8.8 mm
Max Single Day231.4 mm
Heavy Rain Days19
Extreme Events2
Northeast Monsoon (Nov-Feb)
Avg Daily Rain5.8 mm
Max Single Day217.5 mm
Heavy Rain Days40
Extreme Events6
Inter-Monsoon (Mar-Apr, Oct)
Avg Daily Rain7.1 mm
Max Single Day95.3 mm
Heavy Rain Days29
Extreme Events0
Annual Rainfall Trend (1996-2026)
96
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Avg: 2.7k mm/year|
Above avg
Below avg
Top 10 Extreme Rainfall Events (Potential Flood Triggers)
| # | Date | Rainfall (mm) | Month | Severity |
|---|---|---|---|---|
| 1 | 2016-05-15 | 231.4 | May | EXTREME |
| 2 | 2025-11-28 | 217.5 | Nov | EXTREME |
| 3 | 2004-09-26 | 202.2 | Sep | EXTREME |
| 4 | 2020-11-20 | 116.8 | Nov | SEVERE |
| 5 | 2006-11-07 | 111.7 | Nov | SEVERE |
| 6 | 2025-11-27 | 111.1 | Nov | SEVERE |
| 7 | 2021-01-13 | 108.5 | Jan | SEVERE |
| 8 | 2010-11-11 | 101.0 | Nov | SEVERE |
Analysis based on 11,097 days of data for Colombo district (1996-2026) | Source: Open-Meteo Historical Weather API | Data cached for 24 hours
📅 Weather summary, 19 May 2026
427
Total Rainfall (mm)
4.4
Avg per location (mm)
12
Max Rainfall (mm)
92
Locations with rain
💧 Light Rain (<25mm)92
Adhikarigama: 0.4mmAgalawatta: 8mmAgarapathana: 3.3mmAhangama: 4mmAhungalla: 4.6mmAkkaraipattu: 3.6mmAkkarayan: 0.1mmAkuressa: 5.2mmAlawwa: 7mmAluthgama: 5.7mm+82 more
☀️ Dry locations (no rain)4
ButtalaChankanaiChunnakamElephant Pass
Highest Rainfall
Bandaragama
12
mm
Data for Tuesday, May 19, 2026 | Source: Open-Meteo Historical API
🌳 Environmental Factors & Flood Risk (30-Year Analysis)
MEDIUM
Environmental Flood Risk
Based on land use changes since 1994
46/80
Risk Score
Environmental changes have moderately increased flood vulnerability
💡 Reforestation in catchment areas can reduce flood peaks by 20-30%; Improved drainage infrastructure needed in high-density areas; Permeable surfaces and urban green spaces can mitigate urban flooding
🌲
Forest Cover
34.0%(-6.3%)
From 36.3% in 1994
👥
Population Density
356per km²
+29.3% since 1994
🏙️
Urban Population
20.3%
+4.0% since 1994
🌾
Agricultural Land
48.6%
+31.2% since 1994
Environmental Risk Factors
DeforestationMedium Impact
Forest cover reduced from 36.3% to 34.0% (6.3% loss)
Less forest = reduced water absorption = more surface runoff during heavy rain
+13 pts
Population GrowthHigh Impact
Population density increased from 275 to 356 people/sq.km (29.3% increase)
More people = more infrastructure = more impervious surfaces = more flood exposure
+25 pts
UrbanizationMedium Impact
Urban population increased from 16.3% to 20.3% of total
Urban areas have concrete/asphalt surfaces that prevent water absorption
+8 pts
Source: World Bank Open Data API | Period: 1994-2024 | Data cached for 1 week
Zoom Earth - Live Satellite & Wind Map
Real-time satellite imagery, wind speed patterns, cloud cover, and weather radar for Sri Lanka
Live SatelliteWind SpeedCloud CoverWeather Radar
Data Sources:
🌧️ Rainfall: Open-Meteo API
🌊 Rivers: Irrigation Dept
📊 Historical: Open-Meteo Archive
🌳 Deforestation: World Bank
👥 Population: World Bank