Hayama in Summer
In summer (June, July and August), Hayama sees average daytime highs around 24°C and overnight lows near 23°C, with 496 mm of rain over about 37 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Over the season highs climb from about 21°C in early June to 26°C by late August. The sky is clear or mostly clear about 23% of the time across summer, and the air most often feels oppressive.
Summer is Hayama's best season of the year to visit on our travel score. For the whole year in context, see Hayama's year-round climate.
- Avg daytime high
- 24°C
- warmest season of the year
- Avg overnight low
- 23°C
- Rainfall
- 496 mm
- 37 wet days
- Avg wind
- 16 km/h
- Travel score
- 6.1
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Hayama in Summer
Over the season highs climb from about 21°C in early June to 26°C by late August.
A typical summer day in Hayama reaches about 24°C and drops to 23°C overnight. The warmest of the three months is August, the coolest June.
Hayama 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 | 10° / 6° | 89 | 9 | 0.5 | 9.9 | 2.4 |
| Feb | 10° / 6° | 94 | 9.5 | 0.9 | 10.7 | 2.3 |
| Mar | 12° / 8° | 164 | 14.7 | 0.2 | 11.7 | 3.1 |
| Apr | 16° / 12° | 151 | 13.4 | 0 | 12.9 | 4.5 |
| May | 19° / 16° | 159 | 11.9 | 0 | 13.8 | 5.7 |
| Jun | 22° / 20° | 204 | 14 | 0 | 14.3 | 5.6 |
| Jul | 25° / 23° | 167 | 12 | 0 | 14.1 | 6.3 |
| Aug | 27° / 25° | 125 | 10.6 | 0 | 13.3 | 6.5 |
| Sep | 25° / 22° | 208 | 14.1 | 0 | 12.2 | 6.1 |
| Oct | 21° / 18° | 244 | 14.2 | 0 | 11.1 | 5.9 |
| Nov | 17° / 13° | 127 | 12.4 | 0 | 10.1 | 5.1 |
| Dec | 12° / 9° | 82 | 9.5 | 0.1 | 9.7 | 3.6 |
Cloud cover in Summer
The sky is clear or mostly clear about 23% of the time across summer.
Chance of precipitation in Summer
Hayama gets around 496 mm of rain over 37 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 16 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 12 min in early June to 12 h 48 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 4.8 kWh/m².
Hazard calendar for Hayama
In summer, Hayama overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Hayama sits in the Pacific typhoon belt; the season peaks July–October.
Is summer a good time to visit Hayama?
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 Hayama for sightseeing.
What to pack for Hayama in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Hayama sees daytime highs around 24°C and nights near 23°C. Pack rain gear. Worth having: light clothes and sun protection. About 37 days see rain.
Sea temperature near Hayama in Summer
The nearest coast averages about 24°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 17 km away) is warmest in August at about 26°C and coldest in February near 15°C.
It's comfortable for a long swim from May 31 to Nov 26 — about 5.9 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 15 | 16 | 17 | 19 | 21 | 24 | 26 | 25 | 23 | 21 | 18 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing | Warm | Warm | Refreshing | Refreshing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 15 | Cool |
| Mar | 16 | Cool |
| Apr | 17 | Cool |
| May | 19 | Cool |
| Jun | 21 | Refreshing |
| Jul | 24 | Refreshing |
| Aug | 26 | Warm |
| Sep | 25 | Warm |
| Oct | 23 | Refreshing |
| Nov | 21 | Refreshing |
| Dec | 18 | Cool |
UV index in Hayama in Summer
Clear-sky midday UV across summer averages around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Hayama peaks around July 22 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 5 | 7 | 8 | 9 | 10 | 10 | 8 | 6 | 4 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 10 | Very high |
| Aug | 10 | Very high |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 2 | Moderate |
Air quality in Hayama 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 Hayama is worst in April — around 26 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 12 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) | 14 | 25 | 23 | 26 | 21 | 18 | 13 | 12 | 12 | 14 | 14 | 12 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 14 | Moderate |
| Feb | 25 | Moderate |
| Mar | 23 | Moderate |
| Apr | 26 | Moderate |
| May | 21 | Moderate |
| Jun | 18 | Moderate |
| Jul | 13 | Moderate |
| Aug | 12 | Moderate |
| Sep | 12 | Moderate |
| Oct | 14 | Moderate |
| Nov | 14 | Moderate |
| Dec | 12 | Good |
Where is Hayama?
Hayama sits at 35.3°N, 139.6°E, 10 m above sea level, in Japan. The nearest listed city is Zushi, 2.0 km away.
Topography around Hayama
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Hayama.
Within 3 km, the terrain around Hayama has only modest variations in elevation — a maximum elevation change of 207 m around an average of 34 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 237 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,737 m.
The land around Hayama is covered by trees (39%), water (39%) and artificial surfaces (21%) within 3 km, water (55%) and artificial surfaces (26%) within 16 km, and water (41%), trees (34%) and artificial surfaces (20%) within 80 km.
Japan travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 100 V · 50 / 60 Hz
- Prices
- ≈ 65% of US
- price level, 2025
- GDP per capita
- $35,951
- 2025
- Happiness
- 6.1 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.2
- per 100k, 2023
- Road deaths
- 3.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Very low
- EF EPI 446
- 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 Hayama (35.2765°, 139.5773°, elevation 10 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.