Climate Overview
The climate in Haeju is temperate. The average annual temperature is 12°C and approximately 923mm of precipitation falls per year. July is the wettest month, receiving around 217mm of rainfall. Haeju is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are January, December, February, when temperatures can drop to -6°C. Light snow can occur between January and December.
Temperature
Temperatures in Haeju vary considerably across the year, with a 35°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 29°C and the mean temperature sits around 26°C. The coldest month is January, when overnight lows fall to -6°C and the daily average is -2°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between November and December, with a 8°C shift in average temperatures.
Precipitation
Haeju is a moderately rainy area, receiving approximately 923mm of precipitation annually, which averages out to around 77mm per month. The wettest month is July, averaging 217mm of rainfall. August and September also tend to see above-average precipitation. The driest month is January, with just 16mm. That's 201mm less than July, 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 15cm annually. February is the snowiest month with approximately 5cm.
Wind
Haeju is mildly breezy, with an average annual wind speed of 18km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 16km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h 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 19km/h in winter, 19km/h in spring, 16km/h in summer, 17km/h in autumn.
Seasons
89 days until Summer
It is currently spring in Haeju, which began on March 20, 2026. Haeju 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 August at around 29°C, while the coldest stretch bottoms out in January near -6°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 2 to 20°C. Precipitation is moderate at around 167mm for the season, averaging 56mm per month. Winds are moderate at around 19km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 18 to 29°C. Rainfall is heavy, totalling around 485mm across the season with a monthly average of 162mm. Winds are moderate at around 16km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 3 to 25°C. Precipitation is moderate at around 211mm for the season, averaging 70mm per month. Winds are moderate at around 17km/h. Layered clothing works best as temperatures gradually cool — enjoy the crisp air and changing scenery.
Winter
Temperatures range from -6 to 3°C. Rainfall is relatively light, with around 60mm over the season and a monthly average of 20mm. Expect around 12cm of snow accumulation during this period. Winds are moderate at around 19km/h. Warm winter clothing and waterproof boots are a must, and travel may be affected by snow.
Best Time to Visit
The best time to visit Haeju is during May and June, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 89mm per month. By contrast, August can be uncomfortably hot with highs reaching 29°C, while January is the coldest period with lows dropping to -6°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.
Monthly Climate Data
The table below shows monthly climate averages for Haeju 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.