Bilthoven in Summer
In summer (June, July and August), Bilthoven sees average daytime highs around 21°C and overnight lows near 13°C, with 229 mm of rain over about 39 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 21°C. The sky is clear or mostly clear about 17% of the time across summer, and the air most often feels dry.
Summer is Bilthoven's best season of the year to visit on our travel score. For the whole year in context, see Bilthoven's year-round climate.
- Avg daytime high
- 21°C
- warmest season of the year
- Avg overnight low
- 13°C
- Rainfall
- 229 mm
- 39 wet days
- Avg wind
- 13 km/h
- Travel score
- 5.9
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Bilthoven in Summer
Across summer, daytime highs hold fairly steady around 21°C.
A typical summer day in Bilthoven reaches about 21°C and drops to 13°C overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Bilthoven
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Bilthoven 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 (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 6° / 1° | 64 | 12.6 | 1.2 | 8 | 0.3 |
| Feb | 6° / 1° | 54 | 10.7 | 1.5 | 9.5 | 0.6 |
| Mar | 10° / 3° | 55 | 11.5 | 0.8 | 11.5 | 2.0 |
| Apr | 14° / 5° | 51 | 11.3 | 0.1 | 13.6 | 3.8 |
| May | 17° / 9° | 63 | 11.8 | 0 | 15.4 | 5.3 |
| Jun | 20° / 12° | 67 | 11.7 | 0 | 16.4 | 5.8 |
| Jul | 22° / 14° | 82 | 14.1 | 0 | 16 | 6.0 |
| Aug | 22° / 14° | 81 | 13.1 | 0 | 14.4 | 6.0 |
| Sep | 19° / 11° | 67 | 12 | 0 | 12.4 | 5.5 |
| Oct | 14° / 8° | 65 | 12 | 0 | 10.4 | 3.8 |
| Nov | 9° / 5° | 61 | 12.3 | 0.3 | 8.5 | 1.8 |
| Dec | 6° / 2° | 70 | 13.1 | 1.3 | 7.6 | 0.5 |
Cloud cover in Summer
The sky is clear or mostly clear about 17% of the time across summer.
Chance of precipitation in Summer
Bilthoven gets around 229 mm of rain over 39 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 13 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 16 h 06 min in early June to 13 h 30 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 4.9 kWh/m².
Is summer a good time to visit Bilthoven?
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 Bilthoven for sightseeing.
What to pack for Bilthoven in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Bilthoven sees daytime highs around 21°C and nights near 13°C. Pack rain gear. Worth having: light clothes and sun protection. About 39 days see rain.
Sea temperature near Bilthoven in Summer
The nearest coast averages about 17°C 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 56 km away) is warmest in August at about 19°C and coldest in February near 5°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 6 | 5 | 6 | 9 | 12 | 15 | 18 | 19 | 18 | 15 | 11 | 8 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 6 | Bracing |
| Feb | 5 | Bracing |
| Mar | 6 | Bracing |
| Apr | 9 | Bracing |
| May | 12 | Bracing |
| Jun | 15 | Bracing |
| Jul | 18 | Cool |
| Aug | 19 | Cool |
| Sep | 18 | Cool |
| Oct | 15 | Bracing |
| Nov | 11 | Bracing |
| Dec | 8 | Bracing |
UV index in Bilthoven in Summer
Clear-sky midday UV across summer averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Bilthoven peaks around July 15 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 1 | 3 | 4 | 5 | 6 | 6 | 6 | 4 | 2 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | Moderate | High | High | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 1 | Low |
| Mar | 3 | Moderate |
| Apr | 4 | Moderate |
| May | 5 | Moderate |
| Jun | 6 | High |
| Jul | 6 | High |
| Aug | 6 | High |
| Sep | 4 | Moderate |
| Oct | 2 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Air quality in Bilthoven 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 Bilthoven is worst in March — around 20 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (December, 12 µg/m³).
Seasonal pattern from CAMS reanalysis, scaled to Bilthoven's WHO annual average of 16.4 µg/m³.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 14 | 16 | 20 | 20 | 19 | 18 | 16 | 18 | 16 | 14 | 13 | 12 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 14 | Moderate |
| Feb | 16 | Moderate |
| Mar | 20 | Moderate |
| Apr | 20 | Moderate |
| May | 19 | Moderate |
| Jun | 18 | Moderate |
| Jul | 16 | Moderate |
| Aug | 18 | Moderate |
| Sep | 16 | Moderate |
| Oct | 14 | Moderate |
| Nov | 13 | Moderate |
| Dec | 12 | Moderate |
Where is Bilthoven?
Bilthoven sits at 52.1°N, 5.2°E, 6 m above sea level, in The Netherlands. The nearest listed city is Zeist, 5.0 km away.
Topography around Bilthoven
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bilthoven.
Within 3 km, the terrain around Bilthoven has only modest variations in elevation — a maximum elevation change of 30 m around an average of 10 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 83 m; within 80 km, only modest variations in elevation — a maximum elevation change of 140 m.
The land around Bilthoven is covered by trees (68%) within 3 km, trees (39%) and grassland (35%) within 16 km, and grassland (34%) and water (20%) within 80 km.
The Netherlands travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F
- 230 V · 50 Hz
- Prices
- ≈ 84% of US
- price level, 2025
- GDP per capita
- $73,684
- 2025
- Happiness
- 7.2 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 0.7
- per 100k, 2023
- Road deaths
- 4
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Very high
- EF EPI 624
- 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 Bilthoven (52.13°, 5.2014°, elevation 6 m), 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.