Hanko Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Hanko, Southern Finland, Finland. The numbers reflect climate data gathered over a 30-year period, from 1990 to 2020. Now, let's break down all the details for a clearer picture.

Generally, Hanko has a moderate amount of precipitation, averaging 739 mm (29 in) of rain/snowfall annually. However, it does experience a distinct dry season during certain months. Take a look at our detailed charts below to see the seasonal variation.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Significant seasonal changes in precipitation occur throughout the year. During the wettest month, October receives substantial rainfall, averaging 91 mm (3.6 in) of precipitation, recorded across 16 rainy days.

In contrast, the driest month, May brings less rainfall, with 36 mm (1.4 in) over 10 rainy days.

October, the wettest month, has a maximum daytime temperature of 11°C (52°F). During the driest month May you can expect a temperature of 10°C (50°F). For more detailed insights into the city's temperatures, visit our Hanko Temperature page.

Hanko's average annual precipitation is 739 mm (29 in). Let's compare this to some popular worldwide tourist destinations:

Athens, Greece, receives an average annual precipitation of 400 mm (16 in), making it one of the drier Mediterranean climates with rainfall mostly in winter.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.

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.

Precipitation has a very strong role in determining the local climate and ecosystem:

• Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
• Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

For more detailed information about Hanko's weather, including sunshine hours, humidity levels, and temperature data, visit our Hanko Climate page.