West Lake Sammamish weather in April

In April, West Lake Sammamish sees average daytime highs of 57°F and overnight lows near 41°F, with 5.4 in of precipitation across 16.5 wet days and about 13.3 hours of daylight. It is the 7th-warmest and 7th-wettest month of the year here.

Highs climb over the month, from about 55°F in the first days to 60°F by the end. The sky is clear or mostly clear about 13% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 30 min at the start of April to 14 h 06 min by month's end. Set against the rest of the year, April is West Lake Sammamish's 8th-clearest and 6th-windiest month. For the whole year in context, see West Lake Sammamish's year-round climate.

Daytime high
57°
7th warmest
Overnight low
41°
6th coldest
Precipitation
5.4 in
16.5 wet days
Daylight
13 h 24 min
5:27 AM – 6:50 PM
Cloud cover
73%
8th clearest
Wind
5 mph
6th windiest
Solar energy
4.33 kWh/m²
Travel score
3.4
out of 10

West Lake Sammamish is census designated place.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 55°F in the first days to 60°F by the end.

A typical April day in West Lake Sammamish reaches about 57°F in the afternoon and slips back to 41°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 49°F and 67°F. Set against its neighbours, April runs about 5°F warmer than March and about 6°F cooler than May.

30°40°50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
15439
25539
35539
45539
55539
65539
75540
85540
95640
105640
115640
125640
135640
145740
155740
165741
175741
185841
195841
205841
215841
225942
235942
245942
255942
265942
276042
286043
296043
306043

How April really feels in West Lake Sammamish

Once humidity and wind are folded in, April averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

April sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

West Lake Sammamish weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan45° / 35°8.318.73.68.70.8
Feb48° / 36°5.815.52.69.91.5
Mar52° / 37°6.518.71.811.62.2
Apr57° / 41°5.416.50.213.33.4
May63° / 46°3.812.8014.95.1
Jun67° / 50°3.211.4015.75.9
Jul74° / 54°1.36.5015.47.7
Aug74° / 54°1.65.7014.17.9
Sep68° / 49°3.49012.46.6
Oct58° / 43°6.615.1010.63.9
Nov49° / 38°9.018.719.11.6
Dec44° / 35°8.118.43.48.30.6

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 13% of April, with mostly cloudy or overcast conditions the remaining 73%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12476
22377
32377
42377
52278
62278
72377
82377
92278
102377
112476
122476
132575
142575
152872
162872
172872
182971
192971
202971
213070
223070
233070
243169
253070
263070
273169
283169
293169
303268

Chance of precipitation in April

Any precipitationSnow

West Lake Sammamish gets around 5.4 in of rain and snow over 16.5 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 54% and peaks near 58% on the wettest days, and about 0 day brings snow. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
1583
2583
3583
4582
5582
6582
7582
8581
9571
10571
11571
12561
13561
14551
15551
16540
17540
18530
19530
20530
21520
22520
23520
24510
25510
26510
27500
28500
29500
30490

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, April lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
27991
28991
29991
30991

Wind in April

Winds average 5 mph in April.

Across April, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 30 min at the start of April to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 96 minutes over April. Sunrise moves from 5:58 AM to 5:02 AM, and sunset from 6:28 PM to 7:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.55:586:28
212.65:566:30
312.65:536:31
412.75:516:33
512.75:496:34
612.85:476:36
712.95:456:37
812.95:436:39
913.05:416:40
1013.05:396:41
1113.15:376:43
1213.25:356:44
1313.25:336:46
1413.35:316:47
1513.35:296:49
1613.45:276:50
1713.45:256:51
1813.55:236:53
1913.55:216:54
2013.65:206:56
2113.75:186:57
2213.75:166:59
2313.85:147:00
2413.85:127:01
2513.95:107:03
2613.95:097:04
2714.05:077:06
2814.05:057:07
2914.15:037:09
3014.15:027:10

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 4.33 kWh/m².

For context, solar energy here swings from a low near 0.9 kWh/m² to a high of 6.18 kWh/m² in July across the year — April's 4.33 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
13.7Moderate
23.7Moderate
33.8Moderate
43.8Moderate
53.9Moderate
63.9Moderate
74.0Moderate
84.0Moderate
94.0Bright
104.1Bright
114.1Bright
124.2Bright
134.2Bright
144.3Bright
154.3Bright
164.4Bright
174.4Bright
184.5Bright
194.5Bright
204.6Bright
214.6Bright
224.7Bright
234.7Bright
244.7Bright
254.8Bright
264.8Bright
274.9Bright
284.9Bright
294.9Bright
305.0Bright
Planning a trip in April

Hazard calendar for West Lake Sammamish

In seasonPeak

In April, West Lake Sammamish sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

West Lake Sammamish's rainy season runs October–April, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is April a good time to visit West Lake Sammamish?

Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.4
Sightseeing
7th-best month of the year
0.1
Beach & pool
7th-best month of the year

April is a weaker month for outdoor sightseeing in West Lake Sammamish.

What to pack for West Lake Sammamish in April

From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In April, West Lake Sammamish sees daytime highs around 57°F and nights near 41°F. Pack rain gear. Worth having: a warm layer. About 17 days see rain.

rain geara warm layer

UV index in West Lake Sammamish in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in West Lake Sammamish 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 17UV 8Dec 17UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar4Moderate
Apr5Moderate
May7High
Jun6High
Jul8Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in West Lake Sammamish in April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.

Air quality in West Lake Sammamish 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).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodSep 1322 µg/m³Dec 177 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar12Moderate
Apr12Good
May11Good
Jun10Good
Jul10Good
Aug18Moderate
Sep22Moderate
Oct12Good
Nov8Good
Dec7Good
Location & terrain

Where is West Lake Sammamish?

West Lake Sammamish sits at 47.6°N, 122.1°W, 30 ft above sea level, in United States. The nearest listed city is City of Sammamish, 3.7 mi away.

Topography around West Lake Sammamish

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of West Lake Sammamish.

Within 2 miles, the terrain around West Lake Sammamish has significant variations in elevation — a maximum elevation change of 1,076 ft around an average of 272 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,005 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,695 ft.

The land around West Lake Sammamish is covered by trees (52%) and water (32%) within 2 miles, trees (66%) within 10 miles, and trees (76%) within 50 miles.

2 miles
1,076 ft
10 miles
3,005 ft
50 miles
9,695 ft
treesgrasslandartificial surfacesbare terrainwater
April weather nearby: City of Sammamish 3.7 mi · Sammamish 4.3 mi · Issaquah 4.3 mi · Bellevue 5.0 mi · Mercer Island 5.6 mi · Redmond 6.8 mi · Union Hill-Novelty Hill 8.1 mi · Columbia City 8.1 mi

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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 West Lake Sammamish (47.5776°, -122.1012°, elevation 30 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).