Climate Insights for Onsŏng

The climate in Onsŏng is cool. The average annual temperature is 6°C and approximately 700mm of precipitation falls per year. August is the wettest month, receiving around 190mm of rainfall. Onsŏng is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, December, February, when temperatures can drop to -17°C. Light snow can occur between January and December.

Onsŏng has a wide annual temperature range, spanning 43°C from the coldest to warmest months. The warmest month is July, when average highs reach 26°C and the mean temperature sits around 22°C. January brings the harshest conditions, with lows dropping to -17°C and an average temperature of -12°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 10°C shift in average temperatures.

Onsŏng is a relatively dry area, receiving approximately 700mm of precipitation annually, which averages out to around 58mm per month. The wettest month is August, averaging 190mm of rainfall. July and June also tend to see above-average precipitation. The driest month is January, with just 7mm. That's 183mm less than August, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Light snowfall can occur between January and December, totalling around 48cm annually. November is the snowiest month with approximately 12cm.

Onsŏng is mildly breezy, with an average annual wind speed of 15km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 17km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 12km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 5km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 17km/h in winter, 17km/h in spring, 12km/h in summer, 14km/h in autumn.

It is currently spring in Onsŏng, which began on March 20, 2026. Onsŏng is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 26°C, while the coldest stretch bottoms out in January near -17°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Onsŏng is during June and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 16°C with modest rainfall averaging 78mm per month. By contrast, July can be uncomfortably hot with highs reaching 26°C, while January is the coldest period with lows dropping to -17°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Onsŏng based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.