May in Cornwall, England, typically offers a pleasant mix of spring sunshine and mild temperatures, making it an attractive time to visit. Daily high temperatures average around 14-16C (57-61F), while overnight lows rarely dip below 8-10C (46-50F). Rainfall is possible, though less frequent than in the earlier spring months. Sea temperatures remain cool, averaging around 12C (54F).
This period signifies a shift from the more unpredictable weather of early spring towards the warmer summer months. The milder conditions and increasing daylight hours create favorable conditions for exploring the region’s famed coastal paths, gardens, and historic sites. Historically, May has been a popular time for agricultural activities in Cornwall, taking advantage of the warming soil and longer days.