Weather forecast for 10 daysMercer Island, WA
Weather forecast for the weekend
Sunday Oct 18, 2026
- 59°F
- 46°F
Partly Cloudy
- Precip. probability: 18%
- Precipitation: 0"
- Wind: 8mphN 3°
- Humidity: 73%
- UV index: 3
- Sunrise: 7:32 am PDT
- Sunset: 6:15 pm PDT
- details ▼
On Sunday, in Mercer Island, clouds and sunshine will create a dynamic sky throughout the day.
Temperature fluctuations between a moderate 59°F and a chilly 46.4°F are anticipated.
The anticipated daily high is projected to match October's typical maximum of 58.6°F.
Sunrise will be at 7:32 am and sunset at 6:15 pm; the daylight will last for 10h and 43min.
Temperature fluctuations between a moderate 59°F and a chilly 46.4°F are anticipated.
The anticipated daily high is projected to match October's typical maximum of 58.6°F.
Sunrise will be at 7:32 am and sunset at 6:15 pm; the daylight will last for 10h and 43min.
10-day overview
Daily temperatures
Warmest day: Wednesday 64°C.
Coldest period: Saturday - Sunday 54°C.
Coldest period: Saturday - Sunday 54°C.
Chance of precipitation
Highest chance: Sunday 25.10. 36%.
Long-term weather forecast
- Sunday
- Oct 18, 2026
- 59°F
- 46°F
Partly Cloudy
- Precip. probability: 18%
- Precipitation: 0"
- Wind: 8mphN 3°
- Humidity: 73%
- UV index: 3
- Sunrise: 7:32 am PDT
- Sunset: 6:15 pm PDT
- details ▼
- Monday
- Oct 19, 2026
- 61°F
- 45°F
Mostly Cloudy
- Precip. probability: 7%
- Precipitation: 0"
- Wind: 4mphWSW 250°
- Humidity: 69%
- UV index: 2
- Sunrise: 7:34 am PDT
- Sunset: 6:13 pm PDT
- details ▼
- Tuesday
- Oct 20, 2026
- 61°F
- 45°F
Partly Cloudy
- Precip. probability: 22%
- Precipitation: 0"
- Wind: 9mphN 4°
- Humidity: 74%
- UV index: 3
- Sunrise: 7:35 am PDT
- Sunset: 6:11 pm PDT
- details ▼
- Wednesday
- Oct 21, 2026
- 64°F
- 46°F
Partly Cloudy
- Precip. probability: 18%
- Precipitation: 0"
- Wind: 4mphN 351°
- Humidity: 70%
- UV index: 3
- Sunrise: 7:36 am PDT
- Sunset: 6:09 pm PDT
- details ▼
- Thursday
- Oct 22, 2026
- 57°F
- 45°F
Mostly Cloudy
- Precip. probability: 24%
- Precipitation: 0"
- Wind: 5mphWSW 247°
- Humidity: 77%
- UV index: 2
- Sunrise: 7:38 am PDT
- Sunset: 6:08 pm PDT
- details ▼
- Friday
- Oct 23, 2026
- 55°F
- 43°F
Partly Cloudy
- Precip. probability: 23%
- Precipitation: 0.08"
- Wind: 5mphSW 235°
- Humidity: 72%
- UV index: 2
- Sunrise: 7:39 am PDT
- Sunset: 6:06 pm PDT
- details ▼
- Saturday
- Oct 24, 2026
- 54°F
- 43°F
Few Showers
- Precip. probability: 32%
- Precipitation: 0.04"
- Wind: 6mphNNE 31°
- Humidity: 77%
- UV index: 2
- Sunrise: 7:41 am PDT
- Sunset: 6:04 pm PDT
- details ▼
- Sunday
- Oct 25, 2026
- 54°F
- 43°F
Showers
- Precip. probability: 36%
- Precipitation: 0.16"
- Wind: 6mphN 11°
- Humidity: 76%
- UV index: 2
- Sunrise: 7:42 am PDT
- Sunset: 6:02 pm PDT
- details ▼
- Monday
- Oct 26, 2026
- 55°F
- 45°F
Partly Cloudy
- Precip. probability: 22%
- Precipitation: 0.08"
- Wind: 4mphN 8°
- Humidity: 74%
- UV index: 2
- Sunrise: 7:44 am PDT
- Sunset: 6:01 pm PDT
- details ▼
- Tuesday
- Oct 27, 2026
- 55°F
- 45°F
Partly Cloudy
- Precip. probability: 22%
- Precipitation: 0"
- Wind: 6mphWSW 250°
- Humidity: 76%
- UV index: 2
- Sunrise: 7:45 am PDT
- Sunset: 5:59 pm PDT
- details ▼
During the upcoming ten-day period, primarily overcast and occasionally showery weather is expected.
Rainfall is expected on Friday through next Monday.
In the upcoming period, the highest temperature will vary between 53.6°F and 64.4°F, while fluctuations in the night’s lowest temperature will be minimal, as the overnight low will fall between 42.8°F and 46.4°F.
Wednesday is expected to be the warmest, reaching up to 64.4°F; the coldest days will be Saturday and next Sunday, with a maximum of 53.6°F.
Rainfall is expected on Friday through next Monday.
In the upcoming period, the highest temperature will vary between 53.6°F and 64.4°F, while fluctuations in the night’s lowest temperature will be minimal, as the overnight low will fall between 42.8°F and 46.4°F.
Wednesday is expected to be the warmest, reaching up to 64.4°F; the coldest days will be Saturday and next Sunday, with a maximum of 53.6°F.
Updated: Oct 18, 2026 @ 09:29:19 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Frequently asked questions
Today, clouds and sunshine will alternate throughout the day.
Today, the highest temperature will be 59°F, while the lowest temperature will be 46.4°F.
The highest temperature will be in line with the average maximum of 58.6°F in October. The lowest temperature will be also in line with the average low of 44.2°F.
The highest temperature will be in line with the average maximum of 58.6°F in October. The lowest temperature will be also in line with the average low of 44.2°F.
On Sunday, in Mercer Island, sunrise will be at 7:32 am and sunset at 6:15 pm (PDT).
Today, the daylight will last for 10h and 43min.
