Mercer Island Weather in May

With daytime temperatures of 18°C (64°F) and nighttime lows of 9°C (48°F), May in Mercer Island brings pleasant temperatures during the day. Some rainfall is to be expected during the month.

Rainfall in Mercer Island in May

Records from the past 30 years suggest around 12 days of rain, with 56 mm (2.2 in) average for the month. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.

Temperature in Mercer Island in May

In May, Mercer Island gets pleasant temperatures, with highs of 18°C (64°F). Nights cool to around 9°C (48°F). This creates a mild day-to-night pattern that is generally easy to manage with the right clothing. Nights drop to 9°C (48°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.

Sunshine in Mercer Island in May

Expect sunny days throughout the month, with an estimated 254 hours of sunshine. This makes it a pleasant time to visit Mercer Island.

Wind Speed in Mercer Island in May

In May, average wind speeds reach 4 m/s (8 knots), leading to light to moderate breezes. Conditions vary from day to day, with both calm and windier periods.

If you prefer enjoying temperate temperatures and rain-free days, June, July, August and September typically offer the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.