Mercer Island, WA Weather Forecast | 5 Day
Updated: Sat Mar 14th 2026 4:45 AM PDT
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Scattered Showers
Sat 3-14-26
Scattered Showers with a high of 45°F and a low of 30°F. It will likey rain, having a 87% chance of a downpour with an estimated 0.11in. Winds will be light at 5mph and gusts of 7.6mph at 7 PM. The humidity will be on the higher side, averaging about 74%, the maximum being 97% at 7 AM and 46% being its lowest at 1 PM. Barometric pressure is its highest of 30.46inHg at 10 PM, a lowest point of 30.02inHg at 6 AM with an avg 30.28inHg.
- HI: 45°F
- LO: 30°F
- Rainfall: 87% | est. 0.11in
- Snowfall: 0% | est. 0.7in
- Wind
4.3 mph - Humidity
74% avg. - UV Index
0.5 - Air QualityGood
- Sunrise
07:24 AM - Sunset
07:13 PM - Moonrise
05:43 AM - Moonset
02:15 PM - Moon Phase
Waning Crescent
Moderate Rain
Weather Tomorrow, Sun 3-15-26
Moderate Rain with a high of 48°F and a low of 28°F. It will likey rain, having a 88% chance of a downpour with an estimated 0.29in. Winds will be light at 7mph and gusts of 12.2mph at 8 PM. The humidity will be on the higher side, averaging about 71%, the maximum being 96% at 9 PM and 38% being its lowest at 2 PM. Barometric pressure is its highest of 30.5inHg at 2 AM, a lowest point of 30.21inHg at 10 PM with an avg 30.38inHg.
- HI: 48°F
- LO: 28°F
- Rainfall: 88% | est. 0.29in
- Snowfall: 0%
- Wind
6.7 mph - Humidity
71% avg. - UV Index
0.5 - Air QualityGood
- Sunrise
07:22 AM - Sunset
07:15 PM - Moonrise
06:08 AM - Moonset
03:30 PM - Moon Phase
Waning Crescent
Heavy Rain
Mon 3-16-26
Heavy Rain with a high of 52°F and a low of 39°F. It will likey rain, having a 89% chance of a downpour with an estimated 1.4in. Winds will be light at 10mph and gusts of 17.3mph at 12 PM. High humidity with average of 89% is anticipated, the maximum being 98% at 5 AM and 70% being its lowest at 10 PM. Barometric pressure is its highest of 30.19inHg at 11 PM, a lowest point of 29.96inHg at 10 PM with an avg 30.07inHg.
- HI: 52°F
- LO: 39°F
- Rainfall: 89% | est. 1.4in
- Snowfall: 0%
- Wind
9.4 mph - Humidity
89% avg. - UV Index
0.1 - Air QualityGood
- Sunrise
07:20 AM - Sunset
07:16 PM - Moonrise
06:28 AM - Moonset
04:45 PM - Moon Phase
Waning Crescent
Scattered Showers
Tue 3-17-26
Scattered Showers with a high of 53°F and a low of 43°F. It will likey rain, having a 80% chance of a downpour with an estimated 0.13in. Wind will be moderate, blowing around 11mph on average and gusts of 18.2mph at 9 AM. High humidity with average of 94% is anticipated, the maximum being 98% at 11 PM and 90% being its lowest at 1 PM. Barometric pressure is its highest of 30.11inHg at 11 PM, a lowest point of 30inHg at 6 AM with an avg 30.04inHg.
- HI: 53°F
- LO: 43°F
- Rainfall: 80% | est. 0.13in
- Snowfall: 0%
- Wind
10.1 mph - Humidity
94% avg. - UV Index
0 - Air QualityGood
- Sunrise
07:18 AM - Sunset
07:18 PM - Moonrise
06:46 AM - Moonset
06:02 PM - Moon Phase
Waning Crescent
Scattered Showers
Wed 3-18-26
Scattered Showers with a high of 56°F and a low of 48°F. It will likey rain, having a 81% chance of a downpour with an estimated 0.11in. Winds will be light at 8mph and gusts of 13.4mph at 8 PM. High humidity with average of 96% is anticipated, the maximum being 99% at 1 AM and 90% being its lowest at 7 PM. Barometric pressure is its highest of 30.08inHg at 2 AM, a lowest point of 29.99inHg at 6 AM with an avg 30.04inHg.
- HI: 56°F
- LO: 48°F
- Rainfall: 81% | est. 0.11in
- Snowfall: 0%
- Wind
7.4 mph - Humidity
96% avg. - UV Index
2 - Air QualityGood
- Sunrise
07:16 AM - Sunset
07:19 PM - Moonrise
07:03 AM - Moonset
07:21 PM - Moon Phase
Waning Crescent
Scattered Showers
Thu 3-19-26
Scattered Showers with a high of 64°F and a low of 50°F. Rainfall expected to have a 55% chance with an estimated 0.03in. Winds will be light at 7mph and gusts of 13.6mph at 8 PM. High humidity with average of 87% is anticipated, the maximum being 97% at 5 AM and 70% being its lowest at 5 PM. Barometric pressure is its highest of 30.08inHg at 10 AM, a lowest point of 30.02inHg at 5 PM with an avg 30.06inHg.
- HI: 64°F
- LO: 50°F
- Rainfall: 55% | est. 0.03in
- Snowfall: 0%
- Wind
6.5 mph - Humidity
87% avg. - UV Index
3 - Air QualityTBA
- Sunrise
07:14 AM - Sunset
07:21 PM - Moonrise
07:19 AM - Moonset
08:40 PM - Moon Phase
New Moon
This 5-Day weather forecast is valid for ZIP code 98040, accurately covering the area of Mercer Island, WA.
Currently
 |
34°F |
30.04 inHg.
Barometer 100%
Humidity SSE 6.5 mph Wind |
| Mist | ||
National Outlook
Heavy Snow for Upper Midwest and Pacific Northwest Rain: 03-13 to 03-15
Fri Mar 13th 2026, 6:01am PDT
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