10 Hidden gems in Asia you need to visit
Explore 10 hidden gems in Asia offering authentic experiences, from pristine beaches and remote islands to cultural treks and peaceful mountain villages.
This page shows both the average monthly rainfall and the number of rainy days in Katunayaka, Gampaha District, Sri Lanka. These averages rely on historical data collected over 30 years, from 1990 to 2020. Now, let's break down all the details for a clearer picture.
Katunayaka is known for its substantial rainfall, with annual precipitation reaching 2417 mm (95 in). While the overall climate is wet, there are notable seasonal patterns that create interesting contrasts, as demonstrated in our graph below.
The seasons in Katunayaka, bring significant changes in precipitation. The wettest month, October, receives heavy rainfall, with an average of 345 mm (14 in) of precipitation. This rainfall is distributed across 15 rainy days.
In contrast, the driest month, January, experiences much less rainfall, totaling 53 mm (2.1 in) over 4 rainy days. These distinct seasonal differences provide diverse experiences throughout the year.October, the wettest month, has a maximum daytime temperature of 30°C (86°F). The city receives 202 hours of sunshine in this period. During the driest month January you can expect a temperature of 32°C (90°F). For more detailed insights into the city's temperatures, visit our Katunayaka Temperature page.
Average daily rainfall for each day of the month based on long-term records. 47-year average (1976-2025)
Browse day-by-day precipitation records for Katunayaka spanning 51 years. Select any month and year to see actual rainfall and snowfall recorded on each day.
The map below shows the annual precipitation across Sri Lanka. You can also select the different months in case you are interested in a specific month.
Katunayaka's average annual precipitation is 2417 mm (95 in). Let's compare this to some popular worldwide tourist destinations:
In Barcelona, Spain, the average annual precipitation is 620 mm (24 in), evenly distributed across the year with no extreme wet or dry seasons.
Osaka, Japan, experiences 1507 mm (59 in) of rainfall annually, spread across the year with wetter summers.
Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.
Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm (66 in) of annual rainfall, with the heaviest precipitation occurring during September and October.
Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.
Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.
The proximity of a location to a large body of water can significantly affect its rainfall patterns:
For more detailed information about Katunayaka's weather, including sunshine hours, humidity levels, and temperature data, visit our Katunayaka Climate page.
Pick a month to see the average temperature, rainfall and sunshine in Katunayaka - and find the best time to visit.
Temperature Rainfall Sunshine Humidity
See the full Katunayaka climate overview or explore weather in Sri Lanka.
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