About Onsala, Halland's Climate & Weather History

With a population of around 12,300, Onsala sits in Halland, Sweden. The city operates in the Europe/Stockholm time zone.

In 2025, Onsala recorded an average annual temperature of 49°F. The hottest temperatures reached 80°F in July; the coolest were 16°F in February. Total precipitation for the year was 41 inches, with the wettest month being September. Snowfall for the year totaled approximately 6 inches.