Chilaw weather in September
In September, Chilaw sees average daytime highs of 28°C and overnight lows near 26°C, with 180 mm of rain across 24.4 wet days and about 12 hours of daylight. It is the 10th-warmest and 5th-wettest month of the year here.
Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 9% of the time in September, and the air most often feels miserable.
Daylight stretches from about 12 h 06 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Chilaw's 6th-clearest and 4th-windiest month. For the whole year in context, see Chilaw's year-round climate.
- Daytime high
- 28°
- 10th warmest
- Overnight low
- 26°
- 7th coldest
- Rainfall
- 180 mm
- 24.4 wet days
- Daylight
- 12 hours
- 6:04 AM – 6:06 PM
- Cloud cover
- 76%
- 6th clearest
- Wind
- 20 km/h
- 4th windiest
- Solar energy
- 5.4 kWh/m²
- Travel score
- 3.7
- out of 10
Chilaw is large town in Puttalam district, Sri Lanka.
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Day-to-day highs hold fairly steady near 28°C through the month.
A typical September day in Chilaw reaches about 28°C in the afternoon and slips back to 26°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 29°C. Set against its neighbours, September runs on par with August and on par with October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 |
| Avg low (°C) | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 28 | 26 |
| 2 | 28 | 26 |
| 3 | 28 | 26 |
| 4 | 28 | 26 |
| 5 | 28 | 26 |
| 6 | 28 | 26 |
| 7 | 28 | 26 |
| 8 | 28 | 26 |
| 9 | 28 | 26 |
| 10 | 28 | 26 |
| 11 | 28 | 26 |
| 12 | 28 | 26 |
| 13 | 28 | 26 |
| 14 | 28 | 26 |
| 15 | 28 | 26 |
| 16 | 28 | 26 |
| 17 | 28 | 26 |
| 18 | 28 | 26 |
| 19 | 28 | 26 |
| 20 | 28 | 26 |
| 21 | 28 | 26 |
| 22 | 28 | 26 |
| 23 | 28 | 26 |
| 24 | 28 | 26 |
| 25 | 28 | 26 |
| 26 | 28 | 26 |
| 27 | 28 | 26 |
| 28 | 28 | 26 |
| 29 | 28 | 26 |
| 30 | 28 | 26 |
How September really feels in Chilaw
Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Chilaw weather by month
How September compares with the rest of the year at a glance. September is the 10th-warmest and 5th-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 30° / 24° | 37 | 6.1 | 11.6 | 5.7 |
| Feb | 31° / 25° | 33 | 6 | 11.8 | 5.2 |
| Mar | 31° / 26° | 69 | 13.7 | 11.9 | 4.4 |
| Apr | 30° / 26° | 152 | 24.9 | 12.2 | 3.2 |
| May | 30° / 27° | 221 | 28.1 | 12.3 | 3.0 |
| Jun | 29° / 27° | 185 | 25.8 | 12.4 | 3.4 |
| Jul | 28° / 26° | 133 | 22.1 | 12.4 | 4.0 |
| Aug | 28° / 26° | 129 | 21.9 | 12.2 | 4.1 |
| Sep | 28° / 26° | 180 | 24.4 | 12 | 3.7 |
| Oct | 29° / 26° | 298 | 26.1 | 11.8 | 3.5 |
| Nov | 29° / 25° | 261 | 22.2 | 11.7 | 3.8 |
| Dec | 29° / 25° | 131 | 13.5 | 11.6 | 5.0 |
Cloud cover in September
The sky is clear or mostly clear about 9% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 77%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 19 | 19 | 19 | 19 | 20 | 20 | 21 | 22 | 22 | 23 | 24 | 24 | 25 | 25 | 25 | 25 | 26 | 26 | 26 | 25 | 25 | 24 | 24 | 24 | 24 | 24 | 23 | 24 | 24 | 24 |
| Cloudier (%) | 81 | 81 | 81 | 81 | 80 | 80 | 79 | 78 | 78 | 77 | 76 | 76 | 75 | 75 | 75 | 75 | 74 | 74 | 74 | 75 | 75 | 76 | 76 | 76 | 76 | 76 | 77 | 76 | 76 | 76 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 19 | 81 |
| 2 | 19 | 81 |
| 3 | 19 | 81 |
| 4 | 19 | 81 |
| 5 | 20 | 80 |
| 6 | 20 | 80 |
| 7 | 21 | 79 |
| 8 | 22 | 78 |
| 9 | 22 | 78 |
| 10 | 23 | 77 |
| 11 | 24 | 76 |
| 12 | 24 | 76 |
| 13 | 25 | 75 |
| 14 | 25 | 75 |
| 15 | 25 | 75 |
| 16 | 25 | 75 |
| 17 | 26 | 74 |
| 18 | 26 | 74 |
| 19 | 26 | 74 |
| 20 | 25 | 75 |
| 21 | 25 | 75 |
| 22 | 24 | 76 |
| 23 | 24 | 76 |
| 24 | 24 | 76 |
| 25 | 24 | 76 |
| 26 | 24 | 76 |
| 27 | 23 | 77 |
| 28 | 24 | 76 |
| 29 | 24 | 76 |
| 30 | 24 | 76 |
Chance of precipitation in September
Chilaw gets around 180 mm of rain over 24.4 wet days in September. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 81% and peaks near 83% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 77 | 78 | 78 | 78 | 79 | 79 | 79 | 80 | 80 | 80 | 80 | 81 | 81 | 82 | 82 | 83 | 83 | 83 | 83 | 83 | 83 | 83 | 83 | 83 | 82 | 82 | 82 | 81 | 81 | 81 |
| Rain chance (%) | |
|---|---|
| 1 | 77 |
| 2 | 78 |
| 3 | 78 |
| 4 | 78 |
| 5 | 79 |
| 6 | 79 |
| 7 | 79 |
| 8 | 80 |
| 9 | 80 |
| 10 | 80 |
| 11 | 80 |
| 12 | 81 |
| 13 | 81 |
| 14 | 82 |
| 15 | 82 |
| 16 | 83 |
| 17 | 83 |
| 18 | 83 |
| 19 | 83 |
| 20 | 83 |
| 21 | 83 |
| 22 | 83 |
| 23 | 83 |
| 24 | 83 |
| 25 | 82 |
| 26 | 82 |
| 27 | 82 |
| 28 | 81 |
| 29 | 81 |
| 30 | 81 |
Humidity in September
Most of September feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the miserable band about 86% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Oppressive (%) | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 12 | 12 | 12 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 17 | 18 | 19 | 19 |
| Miserable (%) | 86 | 86 | 86 | 86 | 86 | 86 | 87 | 87 | 87 | 87 | 88 | 88 | 88 | 89 | 89 | 89 | 89 | 89 | 89 | 89 | 88 | 87 | 86 | 85 | 84 | 83 | 83 | 82 | 81 | 81 |
| Oppressive (%) | Miserable (%) | |
|---|---|---|
| 1 | 14 | 86 |
| 2 | 14 | 86 |
| 3 | 14 | 86 |
| 4 | 14 | 86 |
| 5 | 14 | 86 |
| 6 | 14 | 86 |
| 7 | 13 | 87 |
| 8 | 13 | 87 |
| 9 | 13 | 87 |
| 10 | 13 | 87 |
| 11 | 12 | 88 |
| 12 | 12 | 88 |
| 13 | 12 | 88 |
| 14 | 11 | 89 |
| 15 | 11 | 89 |
| 16 | 11 | 89 |
| 17 | 11 | 89 |
| 18 | 11 | 89 |
| 19 | 11 | 89 |
| 20 | 11 | 89 |
| 21 | 12 | 88 |
| 22 | 13 | 87 |
| 23 | 14 | 86 |
| 24 | 15 | 85 |
| 25 | 16 | 84 |
| 26 | 17 | 83 |
| 27 | 17 | 83 |
| 28 | 18 | 82 |
| 29 | 19 | 81 |
| 30 | 19 | 81 |
Wind in September
Winds average 20 km/h in September.
Across September, daily wind ranges from about 18 km/h on the calmest days to 21 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 21 | 21 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 19 | 19 | 19 | 19 | 19 | 18 | 18 | 18 | 18 | 18 |
| Feels | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 21 | breezy |
| 2 | 21 | breezy |
| 3 | 21 | breezy |
| 4 | 21 | breezy |
| 5 | 21 | breezy |
| 6 | 20 | breezy |
| 7 | 20 | breezy |
| 8 | 20 | breezy |
| 9 | 20 | breezy |
| 10 | 20 | breezy |
| 11 | 20 | breezy |
| 12 | 20 | breezy |
| 13 | 20 | breezy |
| 14 | 20 | breezy |
| 15 | 20 | breezy |
| 16 | 20 | breezy |
| 17 | 20 | light breeze |
| 18 | 20 | light breeze |
| 19 | 20 | light breeze |
| 20 | 20 | light breeze |
| 21 | 19 | light breeze |
| 22 | 19 | light breeze |
| 23 | 19 | light breeze |
| 24 | 19 | light breeze |
| 25 | 19 | light breeze |
| 26 | 18 | light breeze |
| 27 | 18 | light breeze |
| 28 | 18 | light breeze |
| 29 | 18 | light breeze |
| 30 | 18 | light breeze |
Sunrise & sunset in September
Daylight runs from about 12 h 06 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 12 minutes over September. Sunrise moves from 6:06 AM to 6:02 AM, and sunset from 6:15 PM to 5:58 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.1 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 11.9 | 11.9 |
| Sunrise (AM) | 6:06 | 6:06 | 6:06 | 6:06 | 6:06 | 6:05 | 6:05 | 6:05 | 6:05 | 6:05 | 6:05 | 6:05 | 6:04 | 6:04 | 6:04 | 6:04 | 6:04 | 6:04 | 6:03 | 6:03 | 6:03 | 6:03 | 6:03 | 6:03 | 6:03 | 6:02 | 6:02 | 6:02 | 6:02 | 6:02 |
| Sunset (PM) | 6:15 | 6:14 | 6:14 | 6:13 | 6:13 | 6:12 | 6:12 | 6:11 | 6:10 | 6:10 | 6:09 | 6:09 | 6:08 | 6:08 | 6:07 | 6:06 | 6:06 | 6:05 | 6:05 | 6:04 | 6:03 | 6:03 | 6:02 | 6:02 | 6:01 | 6:01 | 6:00 | 5:59 | 5:59 | 5:58 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.1 | 6:06 | 6:15 |
| 2 | 12.1 | 6:06 | 6:14 |
| 3 | 12.1 | 6:06 | 6:14 |
| 4 | 12.1 | 6:06 | 6:13 |
| 5 | 12.1 | 6:06 | 6:13 |
| 6 | 12.1 | 6:05 | 6:12 |
| 7 | 12.1 | 6:05 | 6:12 |
| 8 | 12.1 | 6:05 | 6:11 |
| 9 | 12.1 | 6:05 | 6:10 |
| 10 | 12.1 | 6:05 | 6:10 |
| 11 | 12.1 | 6:05 | 6:09 |
| 12 | 12.1 | 6:05 | 6:09 |
| 13 | 12.1 | 6:04 | 6:08 |
| 14 | 12.1 | 6:04 | 6:08 |
| 15 | 12.0 | 6:04 | 6:07 |
| 16 | 12.0 | 6:04 | 6:06 |
| 17 | 12.0 | 6:04 | 6:06 |
| 18 | 12.0 | 6:04 | 6:05 |
| 19 | 12.0 | 6:03 | 6:05 |
| 20 | 12.0 | 6:03 | 6:04 |
| 21 | 12.0 | 6:03 | 6:03 |
| 22 | 12.0 | 6:03 | 6:03 |
| 23 | 12.0 | 6:03 | 6:02 |
| 24 | 12.0 | 6:03 | 6:02 |
| 25 | 12.0 | 6:03 | 6:01 |
| 26 | 12.0 | 6:02 | 6:01 |
| 27 | 12.0 | 6:02 | 6:00 |
| 28 | 12.0 | 6:02 | 5:59 |
| 29 | 11.9 | 6:02 | 5:59 |
| 30 | 11.9 | 6:02 | 5:58 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 5.4 kWh/m².
For context, solar energy here swings from a low near 4.7 kWh/m² to a high of 6.51 kWh/m² in March across the year — September's 5.4 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.4 | 5.4 | 5.4 | 5.4 | 5.4 | 5.4 | 5.3 | 5.3 | 5.3 | 5.3 | 5.3 | 5.3 | 5.3 | 5.3 | 5.2 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.5 | Bright |
| 2 | 5.5 | Bright |
| 3 | 5.5 | Bright |
| 4 | 5.5 | Bright |
| 5 | 5.5 | Bright |
| 6 | 5.5 | Bright |
| 7 | 5.5 | Bright |
| 8 | 5.5 | Bright |
| 9 | 5.5 | Bright |
| 10 | 5.5 | Bright |
| 11 | 5.5 | Bright |
| 12 | 5.5 | Bright |
| 13 | 5.5 | Bright |
| 14 | 5.5 | Bright |
| 15 | 5.5 | Bright |
| 16 | 5.4 | Bright |
| 17 | 5.4 | Bright |
| 18 | 5.4 | Bright |
| 19 | 5.4 | Bright |
| 20 | 5.4 | Bright |
| 21 | 5.4 | Bright |
| 22 | 5.3 | Bright |
| 23 | 5.3 | Bright |
| 24 | 5.3 | Bright |
| 25 | 5.3 | Bright |
| 26 | 5.3 | Bright |
| 27 | 5.3 | Bright |
| 28 | 5.3 | Bright |
| 29 | 5.3 | Bright |
| 30 | 5.2 | Bright |
Hazard calendar for Chilaw
In September, Chilaw sits inside its cyclone season. The full year is below, with each hazard's peak months called out.
Chilaw sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.
Is September a good time to visit Chilaw?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a weaker month for outdoor sightseeing in Chilaw.
What to pack for Chilaw in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Chilaw sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.
Sea temperature near Chilaw in September
The nearest coast averages about 28°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 20 km away) is warmest in April at about 30°C and coldest in August near 27°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 28 | 28 | 29 | 30 | 29 | 28 | 27 | 27 | 28 | 28 | 29 | 28 |
| Comfort | Warm | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Warm | Warm | Tropical | Tropical | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 28 | Warm |
| Feb | 28 | Warm |
| Mar | 29 | Tropical |
| Apr | 30 | Tropical |
| May | 29 | Tropical |
| Jun | 28 | Tropical |
| Jul | 27 | Warm |
| Aug | 27 | Warm |
| Sep | 28 | Warm |
| Oct | 28 | Tropical |
| Nov | 29 | Tropical |
| Dec | 28 | Tropical |
UV index in Chilaw in September
Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Chilaw peaks around April 18 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 9 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 10 | 13 | 13 | 13 | 13 | 11 | 12 | 13 | 13 | 12 | 10 | 9 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 10 | Very high |
| Feb | 13 | Extreme |
| Mar | 13 | Extreme |
| Apr | 13 | Extreme |
| May | 13 | Extreme |
| Jun | 11 | Extreme |
| Jul | 12 | Extreme |
| Aug | 13 | Extreme |
| Sep | 13 | Extreme |
| Oct | 12 | Extreme |
| Nov | 10 | Extreme |
| Dec | 9 | Very high |
Air quality in Chilaw in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.
Air quality in Chilaw is worst in March — around 30 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (August, 17 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 23 | 23 | 30 | 28 | 24 | 18 | 17 | 17 | 17 | 19 | 24 | 23 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 23 | Moderate |
| Feb | 23 | Moderate |
| Mar | 30 | Moderate |
| Apr | 28 | Moderate |
| May | 24 | Moderate |
| Jun | 18 | Moderate |
| Jul | 17 | Moderate |
| Aug | 17 | Moderate |
| Sep | 17 | Moderate |
| Oct | 19 | Moderate |
| Nov | 24 | Moderate |
| Dec | 23 | Moderate |
Where is Chilaw?
Chilaw sits at 7.6°N, 79.8°E, 8 m above sea level, in Sri Lanka. The nearest listed city is Negombo, 41 km away.
Topography around Chilaw
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Chilaw.
Within 3 km, the terrain around Chilaw has only modest variations in elevation — a maximum elevation change of 15 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 67 m; within 80 km, large variations in elevation — a maximum elevation change of 977 m.
The land around Chilaw is covered by water (38%) and trees (33%) within 3 km, water (52%) and trees (39%) within 16 km, and trees (53%) and water (37%) within 80 km.
Sri Lanka travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type D / G / M
- 230 V · 50 Hz
- Prices
- ≈ 27% of US
- price level, 2025
- GDP per capita
- $5,002
- 2025
- Happiness
- 4.0 / 10
- World Happiness, 2025
- Safe drinking water
- 47%
- of population, 2024
- Homicide rate
- 3.3
- per 100k, 2019
- Road deaths
- 19.7
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Low
- EF EPI 486
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Chilaw (7.5758°, 79.7953°, elevation 8 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).