Temperatures in May
It's pleasantly warm in May in Mercer Island with an average temperature of 20°C. Temperatures this month range from a low of 17°C to a high of 23°C. At night, you can expect temperatures between 9°C and 13°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Mercer Island in May. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of May
The month of May starts in Mercer Island with mild temperatures, averaging around 20°C during the day and nights close to 10°C. A few showers might pop up in the first days of the month, but the weather remains mostly sunny and dry.
Mid-May
By mid-May, the average daytime temperature stays the same at 20°C, with nights close to 12°C. Not much precipitation expected during this period. It’s mostly dry with sunshine.
End of May
By the end of May, the average daytime temperature in Mercer Island will be around 22°C, with nights close to 13°C. Barely any chance of precipitation. The weather will mostly be dry with lots of sunshine.
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Precipitation in May
In May, there is an average of 55 mm of precipitation, spread over 6 days. The wind speed is around 3 Bft, mostly coming from the West.
The average precipitation chance is 20% per day this month. Though that seems low, there are also a few days with a higher chance of precipitation.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in May for Mercer Island. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Mercer Island in May |
London | ||
|---|---|---|---|
 Average Temperature |
20°C | 18°C | |
 High Temp |
23°C | 21°C | |
| Low Temp |
17°C | 15°C | |
 Total Precipitation |
55 mm | 46 mm | |
| Rainy Days |
6 days | 8 days | |
April
UV index
The UV index is a maximum of 7 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Is May a good time to visit Mercer Island?
Want nice weather? Then May is a great time to be in Mercer Island. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for Mercer Island in May
With 32°C, Mercer Island hit the highest temperature in the last 10 years in May 2023. The lowest daytime temperature in this month was 10°C in 2017. The extreme night temperatures ranged from a low of 4°C to a high of 18°C.
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Daily Temperature in May in Mercer Island
This chart shows the average daily temperatures, both day and night, for each day in May in Mercer Island, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in May in Mercer Island
The chart below shows the average daily precipitation in May for Mercer Island, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for May, you can expect around 6 days of rain in Mercer Island.
Daily UV Index in May in Mercer Island
This chart shows the average daily UV index in May in Mercer Island, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in May in Mercer Island Over the Years
This chart shows the average temperature in May in Mercer Island, measured in degrees Celsius, over the past years.
Total Precipitation in May in Mercer Island Over the Years
This chart shows the average precipitation in May in Mercer Island, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in May for Mercer Island
Click on a specific day in May for detailed info on the typical weather on that day in Mercer Island. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in May in Mercer Island
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Average Weather in Mercer Island by Month
Click on a month below to see detailed weather info for Mercer Island. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Mercer Island for all months at once
