Issaquah in Winter
In winter (December, January and February), Issaquah sees average daytime highs around 46°F and overnight lows near 35°F, with 22.2 in of precipitation over about 53 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Over the season highs climb from about 45°F in early December to 49°F by late February. The sky is clear or mostly clear about 16% of the time across winter, and the air most often feels dry.
Winter is Issaquah's weakest season of the year to visit on our travel score. For the whole year in context, see Issaquah's year-round climate.
- Avg daytime high
- 46°F
- coldest season of the year
- Avg overnight low
- 35°F
- Precipitation
- 22.2 in
- 53 wet days
- Avg wind
- 6 mph
- Travel score
- 1.0
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Issaquah in Winter
Over the season highs climb from about 45°F in early December to 49°F by late February.
A typical winter day in Issaquah reaches about 46°F and drops to 35°F overnight. The warmest of the three months is February, the coolest December.
How winter really feels in Issaquah
Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 90 that feel at or below 32°F.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Issaquah weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 45° / 35° | 8.3 | 18.7 | 3.6 | 8.7 | 0.8 |
| Feb | 48° / 36° | 5.8 | 15.5 | 2.6 | 9.9 | 1.5 |
| Mar | 52° / 37° | 6.5 | 18.7 | 1.8 | 11.6 | 2.2 |
| Apr | 57° / 41° | 5.4 | 16.5 | 0.2 | 13.3 | 3.4 |
| May | 63° / 46° | 3.8 | 12.8 | 0 | 14.9 | 5.1 |
| Jun | 67° / 50° | 3.2 | 11.4 | 0 | 15.7 | 5.9 |
| Jul | 74° / 54° | 1.3 | 6.5 | 0 | 15.4 | 7.7 |
| Aug | 74° / 54° | 1.6 | 5.7 | 0 | 14.1 | 7.9 |
| Sep | 68° / 49° | 3.4 | 9 | 0 | 12.4 | 6.6 |
| Oct | 58° / 43° | 6.6 | 15.1 | 0 | 10.6 | 3.9 |
| Nov | 49° / 38° | 9.0 | 18.7 | 1 | 9.1 | 1.6 |
| Dec | 44° / 35° | 8.1 | 18.4 | 3.4 | 8.3 | 0.6 |
Cloud cover in Winter
The sky is clear or mostly clear about 16% of the time across winter.
Chance of precipitation in Winter
Issaquah gets around 22.2 in of rain and snow over 53 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 6 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 8 h 30 min in early December to 10 h 42 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 1.3 kWh/m².
Hazard calendar for Issaquah
In winter, Issaquah overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Issaquah's rainy season runs October–April, when most of the year's rain falls.
Is winter a good time to visit Issaquah?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Issaquah.
What to pack for Issaquah in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Issaquah sees daytime highs around 46°F and nights near 35°F. Pack a warm layer and rain gear. Worth having: a heavy coat. About 53 days see rain.
UV index in Issaquah in Winter
Clear-sky midday UV across winter averages around 1. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Issaquah peaks around July 17 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 17 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 1 | 4 | 5 | 7 | 6 | 8 | 6 | 4 | 3 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | High | High | Very high | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 1 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | Moderate |
| May | 7 | High |
| Jun | 6 | High |
| Jul | 8 | Very high |
| Aug | 6 | High |
| Sep | 4 | Moderate |
| Oct | 3 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Air quality in Issaquah in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Issaquah is worst in September — around 22 µg/m³ PM2.5 (moderate), about 3.4× the cleanest month (December, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 8 | 9 | 12 | 12 | 11 | 10 | 10 | 18 | 22 | 12 | 8 | 7 |
| Level | Good | Good | Moderate | Good | Good | Good | Good | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 9 | Good |
| Mar | 12 | Moderate |
| Apr | 12 | Good |
| May | 11 | Good |
| Jun | 10 | Good |
| Jul | 10 | Good |
| Aug | 18 | Moderate |
| Sep | 22 | Moderate |
| Oct | 12 | Good |
| Nov | 8 | Good |
| Dec | 7 | Good |
Where is Issaquah?
Issaquah sits at 47.5°N, 122.0°W, 108 ft above sea level, in United States. The nearest listed city is West Lake Sammamish, 4.3 mi away.
Topography around Issaquah
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Issaquah.
Within 2 miles, the terrain around Issaquah has large variations in elevation — a maximum elevation change of 1,998 ft around an average of 512 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,002 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 14,413 ft.
The land around Issaquah is covered by trees (78%) within 2 miles, trees (77%) within 10 miles, and trees (76%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Issaquah (47.5301°, -122.0326°, elevation 108 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.