Northbrook in Summer
In summer (June, July and August), Northbrook sees average daytime highs around 75°F and overnight lows near 68°F, with 10.3 in of rain over about 32 wet days across the season. It is the warmest season of the year and the 3rd-wettest season.
Over the season highs climb from about 66°F in early June to 76°F by late August. The sky is clear or mostly clear about 39% of the time across summer, and the air most often feels muggy.
Summer is Northbrook's best season of the year to visit on our travel score. For the whole year in context, see Northbrook's year-round climate.
- Avg daytime high
- 75°F
- warmest season of the year
- Avg overnight low
- 68°F
- Rainfall
- 10.3 in
- 32 wet days
- Avg wind
- 10 mph
- Travel score
- 6.8
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Northbrook in Summer
Over the season highs climb from about 66°F in early June to 76°F by late August.
A typical summer day in Northbrook reaches about 75°F and drops to 68°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Northbrook
Once humidity and wind are folded in, summer brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Northbrook 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 | 30° / 21° | 2.9 | 9.8 | 7 | 9.3 | 0.0 |
| Feb | 31° / 21° | 2.4 | 7.7 | 5.1 | 10.3 | 0.0 |
| Mar | 37° / 29° | 3.0 | 9.8 | 3.2 | 11.6 | 0.0 |
| Apr | 46° / 39° | 4.8 | 12 | 1.4 | 13.1 | 1.3 |
| May | 58° / 50° | 4.1 | 11.7 | 0 | 14.4 | 4.1 |
| Jun | 71° / 64° | 3.5 | 10.5 | 0 | 15 | 6.5 |
| Jul | 78° / 70° | 3.1 | 10.5 | 0 | 14.8 | 6.8 |
| Aug | 77° / 70° | 3.8 | 10.7 | 0 | 13.7 | 7.0 |
| Sep | 71° / 63° | 3.3 | 9.5 | 0 | 12.3 | 6.8 |
| Oct | 58° / 51° | 4.0 | 10.5 | 0.1 | 10.8 | 4.4 |
| Nov | 46° / 39° | 3.4 | 10 | 1.3 | 9.6 | 1.2 |
| Dec | 36° / 28° | 3.1 | 10 | 4.9 | 9 | 0.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 39% of the time across summer.
Chance of precipitation in Summer
Northbrook gets around 10.3 in of rain over 32 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 48 min in early June to 13 hours 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 6.2 kWh/m².
Is summer a good time to visit Northbrook?
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 a reasonable time to visit Northbrook for sightseeing.
What to pack for Northbrook in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Northbrook sees daytime highs around 75°F and nights near 68°F. Pack sun protection. Worth having: light clothes and rain gear. About 32 days see rain.
Sea temperature near Northbrook in Summer
The nearest coast averages about 66°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 11 mi away) is warmest in August at about 72°F and coldest in February near 36°F.
It's comfortable for a long swim from Jul 14 to Sep 14 — about 2.1 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 38 | 36 | 36 | 39 | 44 | 56 | 69 | 72 | 68 | 58 | 48 | 42 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Refreshing | Refreshing | Refreshing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 38 | Bracing |
| Feb | 36 | Bracing |
| Mar | 36 | Bracing |
| Apr | 39 | Bracing |
| May | 44 | Bracing |
| Jun | 56 | Bracing |
| Jul | 69 | Refreshing |
| Aug | 72 | Refreshing |
| Sep | 68 | Refreshing |
| Oct | 58 | Bracing |
| Nov | 48 | Bracing |
| Dec | 42 | Bracing |
UV index in Northbrook in Summer
Clear-sky midday UV across summer averages around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Northbrook peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 4 | 6 | 7 | 9 | 9 | 8 | 6 | 3 | 2 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 7 | Very high |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Northbrook 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 Northbrook is worst in July — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 10 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) | 12 | 15 | 18 | 19 | 20 | 21 | 21 | 18 | 15 | 10 | 10 | 11 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 12 | Moderate |
| Feb | 15 | Moderate |
| Mar | 18 | Moderate |
| Apr | 19 | Moderate |
| May | 20 | Moderate |
| Jun | 21 | Moderate |
| Jul | 21 | Moderate |
| Aug | 18 | Moderate |
| Sep | 15 | Moderate |
| Oct | 10 | Good |
| Nov | 10 | Good |
| Dec | 11 | Good |
Where is Northbrook?
Northbrook sits at 42.1°N, 87.8°W, 646 ft above sea level, in United States. The nearest listed city is Deerfield, 3.1 mi away.
Topography around Northbrook
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Northbrook.
Within 2 miles, the terrain around Northbrook has only modest variations in elevation — a maximum elevation change of 135 ft around an average of 673 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 240 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 892 ft.
The land around Northbrook is covered by trees (46%) and artificial surfaces (35%) within 2 miles, trees (35%), artificial surfaces (29%) and water (25%) within 10 miles, and water (40%) 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 Northbrook (42.1275°, -87.829°, elevation 646 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.