Mill Creek in Summer
In summer (June, July and August), Mill Creek sees average daytime highs around 70°F and overnight lows near 55°F, with 5.6 in of rain over about 22 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 64°F in early June to 70°F by late August. The sky is clear or mostly clear about 40% of the time across summer, and the air most often feels dry.
Summer is Mill Creek's best season of the year to visit on our travel score. For the whole year in context, see Mill Creek's year-round climate.
- Avg daytime high
- 70°F
- warmest season of the year
- Avg overnight low
- 55°F
- Rainfall
- 5.6 in
- 22 wet days
- Avg wind
- 5 mph
- Travel score
- 7.1
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Mill Creek in Summer
Over the season highs climb from about 64°F in early June to 70°F by late August.
A typical summer day in Mill Creek reaches about 70°F and drops to 55°F overnight. The warmest of the three months is August, the coolest June.
Mill Creek weather by month
How the three summer months (June, July and August) 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 | 46° / 39° | 7.1 | 18.3 | 2.1 | 8.6 | 0.9 |
| Feb | 48° / 39° | 4.7 | 14.9 | 1.8 | 9.9 | 1.5 |
| Mar | 51° / 41° | 5.5 | 17.8 | 0.8 | 11.6 | 2.1 |
| Apr | 56° / 44° | 4.4 | 15.4 | 0.1 | 13.4 | 3.2 |
| May | 62° / 48° | 3.1 | 12.5 | 0 | 14.9 | 4.9 |
| Jun | 66° / 52° | 2.8 | 10.7 | 0 | 15.7 | 5.9 |
| Jul | 71° / 56° | 1.3 | 6 | 0 | 15.4 | 7.6 |
| Aug | 72° / 56° | 1.5 | 5.2 | 0 | 14.1 | 7.7 |
| Sep | 66° / 53° | 2.8 | 8.7 | 0 | 12.4 | 6.5 |
| Oct | 58° / 47° | 5.6 | 14.6 | 0 | 10.6 | 3.8 |
| Nov | 50° / 42° | 7.8 | 18.1 | 0.6 | 9.1 | 1.7 |
| Dec | 45° / 38° | 7.1 | 17.9 | 2.1 | 8.3 | 0.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 40% of the time across summer.
Chance of precipitation in Summer
Mill Creek gets around 5.6 in of rain over 22 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 5 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 h 30 min in early June to 13 h 18 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.6 kWh/m².
Hazard calendar for Mill Creek
None of Mill Creek's seasonal hazards peak in summer. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
Mill Creek's rainy season runs October–April, when most of the year's rain falls.
Is summer a good time to visit Mill Creek?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is one of the better times to visit Mill Creek for general sightseeing.
What to pack for Mill Creek in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Mill Creek sees daytime highs around 70°F and nights near 55°F. Pack sun protection. Worth having: light clothes and rain gear. About 22 days see rain.
Sea temperature near Mill Creek in Summer
The nearest coast averages about 53°F across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 36 mi away) is warmest in August at about 53°F and coldest in February near 46°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 46 | 46 | 47 | 48 | 50 | 52 | 53 | 53 | 53 | 50 | 49 | 47 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 46 | Bracing |
| Feb | 46 | Bracing |
| Mar | 47 | Bracing |
| Apr | 48 | Bracing |
| May | 50 | Bracing |
| Jun | 52 | Bracing |
| Jul | 53 | Bracing |
| Aug | 53 | Bracing |
| Sep | 53 | Bracing |
| Oct | 50 | Bracing |
| Nov | 49 | Bracing |
| Dec | 47 | Bracing |
UV index in Mill Creek in Summer
Clear-sky midday UV across summer averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Mill Creek 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 18 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 Mill Creek in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Mill Creek is worst in August — around 20 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (December, 6 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 | 10 | 12 | 12 | 13 | 11 | 10 | 20 | 18 | 11 | 7 | 6 |
| Level | Good | Good | Moderate | Good | Moderate | Good | Good | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 10 | Good |
| Mar | 12 | Moderate |
| Apr | 12 | Good |
| May | 13 | Moderate |
| Jun | 11 | Good |
| Jul | 10 | Good |
| Aug | 20 | Moderate |
| Sep | 18 | Moderate |
| Oct | 11 | Good |
| Nov | 7 | Good |
| Dec | 6 | Good |
Where is Mill Creek?
Mill Creek sits at 47.9°N, 122.2°W, 377 ft above sea level, in United States. The nearest listed city is Martha Lake, 1.9 mi away.
Topography around Mill Creek
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Mill Creek.
Within 2 miles, the terrain around Mill Creek has only modest variations in elevation — a maximum elevation change of 358 ft around an average of 413 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 778 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,585 ft.
The land around Mill Creek is covered by trees (65%) and artificial surfaces (27%) within 2 miles, trees (53%) within 10 miles, and trees (70%) 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 Mill Creek (47.8601°, -122.2043°, elevation 377 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.