The climate in Haeju during May can be summarized as mild and a little damp.
May is in the spring in Haeju and is typically the 5th warmest month of the year. Daytime maximum temperatures average around 20°C (69°F), whilst at night 10°C (50°F) is normal.
| Daytime temperature | 20.4°C 68.7°F | 
|---|---|
| Nightly temperature | 9.8°C 49.6°F | 
| Average temperature | 15.1°C 59.2°F | 
| Daily sunshine | 8.9 hrs | 
| Avg rainfall | 83 mm 3.2 ins | 
| Rainy days | 8 days | 
| Sea temperature | 11.4°C 52.6°F | 
| Humidity | 68% | 
| Windspeed | 10.1kph 6 mph | 
On average May is the 5th wettest month of the year in Haeju with around 83mm 3.2 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.
On the flip side this corresponds to an average of 8.9 hours of sunshine per day.
				
						
						The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Haeju in May 2025.
| Hottest month: | August | 28°C 82.4°F | 
|---|---|---|
| Driest month: | February | 15mm 0.6ins | 
| Sunniest month: | October | 7.6hrs | 
| Coldest month: | January | -1.2°C 29.8°F | 
| Wettest month: | July | 342mm 13.5ins |