May in South Hill averages a daily high of 17.1°C with nights around 6.8°C. Expect roughly 13.6 wet days totalling 70.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit South Hill is July–September.
Based on MCMILLIN RESERVOIR, WA US (1.2km), 1995–2024. 17 years of May data.