Weather forecast for tomorrowMercer Island, WA
Weather forecast for tomorrow
Sunday Oct 18, 2026
- 59°F
- 46°F
Partly Cloudy
- Precip. probability: 15%
- Precipitation: 0"
- Wind: 8mphN 2°
- Humidity: 73%
- UV index: 3
- Sunrise: 7:32 am PDT
- Sunset: 6:15 pm PDT
- details ▼
Tomorrow, on Sunday, October 18, sunny moments will alternate with patchy cloud cover.
Temperatures are expected to peak at a mild 59°F and drop to a minimum of a chilly 46.4°F.
The highest temperature for tomorrow is expected to reflect October's average of 58.6°F.
Sunrise will be at 7:32 am and sunset at 6:15 pm; tomorrow's daylight will last for 10h and 43min.
Temperatures are expected to peak at a mild 59°F and drop to a minimum of a chilly 46.4°F.
The highest temperature for tomorrow is expected to reflect October's average of 58.6°F.
Sunrise will be at 7:32 am and sunset at 6:15 pm; tomorrow's daylight will last for 10h and 43min.
Hourly overview
Hourly temperatures
Warmest hour: 3 pm 57°C.
Coldest period: 6 am - 9 am 46°C.
Coldest period: 6 am - 9 am 46°C.
Chance of precipitation
Highest chance: 6 am 15%.
Hourly weather forecast
- 12 am
- 52°F
- Feels like:50°F
Clear
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 4mphNE 34°
- Humidity: 78%
- Pressure: 30.24"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 2 am
- 48°F
- Feels like:48°F
Clear
- Precip. probability: 7%
- Precipitation: 0"
- Wind: 2mphNE 41°
- Humidity: 83%
- Pressure: 30.24"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 4 am
- 46°F
- Feels like:46°F
Clear
- Precip. probability: 9%
- Precipitation: 0"
- Wind: 3mphNE 45°
- Humidity: 87%
- Pressure: 30.21"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 6 am
- 46°F
- Feels like:46°F
Clear
- Precip. probability: 15%
- Precipitation: 0"
- Wind: 3mphNE 37°
- Humidity: 90%
- Pressure: 30.21"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
Sunrise: 7:32 am
- 8 am
- 45°F
- Feels like:45°F
Sunny
- Precip. probability: 15%
- Precipitation: 0"
- Wind: 2mphNNE 23°
- Humidity: 96%
- Pressure: 30.18"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 10 am
- 50°F
- Feels like:48°F
Mostly Sunny
- Precip. probability: 6%
- Precipitation: 0"
- Wind: 4mphNNE 17°
- Humidity: 82%
- Pressure: 30.18"Hg
- Visibility: 10mi
- UV index: 1
- details ▼
- 12 pm
- 55°F
- Feels like:54°F
Partly Cloudy
- Precip. probability: 10%
- Precipitation: 0"
- Wind: 6mphN 3°
- Humidity: 70%
- Pressure: 30.15"Hg
- Visibility: 10mi
- UV index: 2
- details ▼
- 2 pm
- 57°F
- Feels like:55°F
Partly Cloudy
- Precip. probability: 7%
- Precipitation: 0"
- Wind: 8mphN 352°
- Humidity: 62%
- Pressure: 30.09"Hg
- Visibility: 10mi
- UV index: 2
- details ▼
- 4 pm
- 57°F
- Feels like:55°F
Partly Cloudy
- Precip. probability: 2%
- Precipitation: 0"
- Wind: 8mphNNW 348°
- Humidity: 60%
- Pressure: 30.03"Hg
- Visibility: 10mi
- UV index: 1
- details ▼
- 6 pm
- 55°F
- Feels like:54°F
Mostly Cloudy
- Precip. probability: 2%
- Precipitation: 0"
- Wind: 6mphNNW 345°
- Humidity: 65%
- Pressure: 30"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
Sunset: 6:15 pm
- 8 pm
- 52°F
- Feels like:52°F
Mostly Cloudy
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 3mphN 353°
- Humidity: 77%
- Pressure: 29.97"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 10 pm
- 50°F
- Feels like:50°F
Cloudy
- Precip. probability: 6%
- Precipitation: 0"
- Wind: 3mphN 7°
- Humidity: 83%
- Pressure: 29.94"Hg
- Visibility: 7mi
- UV index: 0
- details ▼
Tomorrow, on Sunday, primarily overcast and occasionally clear weather is anticipated.
The temperature will vary between a minimum of 44.6°F and a maximum of 57.2°F. The warmest part of the day will be from 1 pm to 5 pm.
Tomorrow, expect conditions in line with October's usual high temperature. The minimum temperature will be also close to October's average low of 44.2°F.
The temperature will vary between a minimum of 44.6°F and a maximum of 57.2°F. The warmest part of the day will be from 1 pm to 5 pm.
Tomorrow, expect conditions in line with October's usual high temperature. The minimum temperature will be also close to October's average low of 44.2°F.
Updated: Oct 17, 2026 @ 14:56:21 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
On Sunday, moments of sunshine will break through the patchy clouds.
Tomorrow, the maximum temperature will be 59°F, while the minimum temperature will be 46.4°F.
Tomorrow, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature tomorrow will be also in line with the average low temperature.
Tomorrow, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature tomorrow will be also in line with the average low temperature.
On Sunday, in Mercer Island, sunrise will be at 7:32 am and sunset at 6:15 pm (PDT).
In Mercer Island, tomorrow, there will be 10h and 43min of daylight.
