Mercer Island Weather in October

During October, Mercer Island experiences moderate daytime temperatures of 16°C (61°F) and cooler nights around 8°C (46°F). Expect quite a bit of rainfall. Around 102 mm (4 in) is typical.

Rainfall in Mercer Island in October

Climate statistics over the past 30 years suggest around 15 days of rain, with 102 mm (4 in) average for the month. Wet weather is a regular and significant part of this month. Frequent days of rain combined with high totals means proper waterproofs are worth packing.

Temperature in Mercer Island in October

Expect highs of 16°C (61°F) in Mercer Island in October, with nights dropping to around 8°C (46°F). This creates a mild day-to-night pattern that is generally easy to manage with the right clothing. Nights fall to 8°C (46°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.

Sunshine in Mercer Island in October

The city usually sees around 143 hours of sunlight, indicating a moderately sunny period.

Wind Speed in Mercer Island in October

October sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. June, July, August and September typically offer the best weather for Mercer Island.

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• January
• February
• March
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• May
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• October
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For a detailed overview over the year and the best time to visit the United States of America, check out our Mercer Island's climate page.

Mercer Island Temperature in October

Min Temperature 8°C (46°F)  

Max Temperature 16°C (61°F)  

Chance of Rain 50%  

Precipitation 102 mm (4 in)  

Rainy days 15 days  

Humidity 78% *  

Windspeed 4 m/s (8 knots) *  

Sunshine 143 hours *  

Percentage Sunshine 42% *  

* Data from: Seattle, the United States of America (15 KM, 9 Miles).

What to Wear in Mercer Island in October

Pack for changing conditions in Mercer Island in October. Bring a mix of short and long sleeves, a warm layer like a hoodie or light jacket, and comfortable pants. The key is being able to add or remove layers as the days goes by. Prepare for significant rainfall with proper waterproof clothing and shoes. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Mercer Island in October

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

5/10

Cycling

5/10

Walking

5/10

Camping

3/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Mercer Island's climate page.

More climate data for Mercer Island

Temperature Rainfall Sunshine Humidity Wind Speed

See the full Mercer Island climate overview or explore weather in the United States of America.