Last updated: June 24, 2025
In May, the average temperature in Washington, United States hovers around 18°C (65°F), with extremes that can dip to a chilly 0°C (32°F) and soar to a warm 32°C (90°F). With 147 mm (5.8 in) of precipitation spread over 16 days, be prepared for a fair share of rainy weather. Coupled with an average humidity of 82%, the climate can feel quite humid, making it important to stay hydrated and comfortable during your visit!
In May in Washington, the average temperature is 18°C (65°F). Maximums can reach 32°C (90°F), and minimums can be as low as 0°C (32°F). This makes Washington an ideal destination for travelers seeking a blend of warm days and cooler nights.
In Washington in May, the precipitation amount is 147 mm (5.8 in) spread over 16 days.
In Washington in May, humidity is 82%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace that can quickly leave travelers feeling fatigued and in need of frequent breaks to stay refreshed and hydrated.
In Washington in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Washington.
UV Risk Categories
Weather in Washington varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Washington, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | 1°C (34°F) | 91 mm (3.6 inches) | 88% | moderate |
February Weather | 4°C (39°F) | 125 mm (4.9 inches) | 88% | moderate |
March Weather | 7°C (46°F) | 115 mm (4.5 inches) | 88% | high |
April Weather | 12°C (55°F) | 143 mm (5.6 inches) | 86% | very high |
May Weather | 18°C (65°F) | 147 mm (5.8 inches) | 82% | very high |
June Weather | 22°C (72°F) | 153 mm (6.0 inches) | 84% | very high |
July Weather | 25°C (77°F) | 112 mm (4.4 inches) | 82% | very high |
August Weather | 24°C (75°F) | 123 mm (4.8 inches) | 73% | very high |
September Weather | 21°C (70°F) | 104 mm (4.1 inches) | 73% | very high |
October Weather | 15°C (60°F) | 113 mm (4.4 inches) | 81% | high |
November Weather | 7°C (45°F) | 82 mm (3.2 inches) | 89% | moderate |
December Weather | 4°C (39°F) | 117 mm (4.6 inches) | 86% | moderate |