Kertosono in Summer
In summer (December, January and February), Kertosono sees average daytime highs around 31°C and overnight lows near 24°C, with 1068 mm of rain over about 83 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 31°C. The sky is clear or mostly clear about 2% of the time across summer, and the air most often feels oppressive.
Summer is Kertosono's weakest season of the year to visit on our travel score. For the whole year in context, see Kertosono's year-round climate.
- Avg daytime high
- 31°C
- coldest season of the year
- Avg overnight low
- 24°C
- Rainfall
- 1068 mm
- 83 wet days
- Avg wind
- 5 km/h
- Travel score
- 2.4
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Kertosono in Summer
Across summer, daytime highs hold fairly steady around 31°C.
A typical summer day in Kertosono reaches about 31°C and drops to 24°C overnight. The warmest of the three months is December, the coolest February.
How summer really feels in Kertosono
Once humidity and wind are folded in, summer brings about 90 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Kertosono weather by month
How the three summer months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 31° / 24° | 379 | 29 | 12.4 | 2.4 |
| Feb | 31° / 24° | 368 | 27.3 | 12.2 | 2.3 |
| Mar | 31° / 24° | 318 | 28.2 | 12.1 | 2.4 |
| Apr | 31° / 24° | 181 | 22.7 | 11.8 | 2.9 |
| May | 31° / 23° | 78 | 12.5 | 11.7 | 4.1 |
| Jun | 31° / 23° | 35 | 6.8 | 11.6 | 4.7 |
| Jul | 31° / 22° | 15 | 3.3 | 11.6 | 5.1 |
| Aug | 32° / 22° | 5 | 1.2 | 11.8 | 5.0 |
| Sep | 33° / 22° | 14 | 2.1 | 12 | 4.3 |
| Oct | 33° / 23° | 61 | 8.7 | 12.2 | 3.4 |
| Nov | 33° / 24° | 168 | 19 | 12.3 | 2.6 |
| Dec | 32° / 24° | 321 | 26.2 | 12.4 | 2.5 |
Cloud cover in Summer
The sky is clear or mostly clear about 2% of the time across summer.
Chance of precipitation in Summer
Kertosono gets around 1068 mm of rain over 83 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 5 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 12 h 24 min in early December to 12 h 12 min by late February. 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 4.7 kWh/m².
Hazard calendar for Kertosono
In summer, Kertosono overlaps its monsoon season. The full year is below, with each hazard's peak months called out.
Kertosono's monsoon runs December–April, when most of the year's rain falls.
Is summer a good time to visit Kertosono?
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 weaker month for outdoor sightseeing in Kertosono.
What to pack for Kertosono in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Kertosono sees daytime highs around 31°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 83 days see rain.
UV index in Kertosono in Summer
Clear-sky midday UV across summer averages around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Kertosono peaks around March 18 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 14 at about 7 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 13 | 11 | 13 | 11 | 9 | 7 | 9 | 11 | 13 | 12 | 10 | 12 |
| Level | Extreme | Extreme | Extreme | Extreme | Very high | High | Very high | Extreme | Extreme | Extreme | Very high | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 13 | Extreme |
| Feb | 11 | Extreme |
| Mar | 13 | Extreme |
| Apr | 11 | Extreme |
| May | 9 | Very high |
| Jun | 7 | High |
| Jul | 9 | Very high |
| Aug | 11 | Extreme |
| Sep | 13 | Extreme |
| Oct | 12 | Extreme |
| Nov | 10 | Very high |
| Dec | 12 | Extreme |
Air quality in Kertosono 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 Kertosono is worst in May — around 64 µg/m³ PM2.5 (unhealthy), and holds fairly steady the rest of the year.
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 44 | 45 | 53 | 59 | 64 | 60 | 54 | 48 | 47 | 49 | 48 | 43 |
| Level | Poor | Poor | Poor | Unhealthy | Unhealthy | Unhealthy | Poor | Poor | Poor | Poor | Poor | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 44 | Poor |
| Feb | 45 | Poor |
| Mar | 53 | Poor |
| Apr | 59 | Unhealthy |
| May | 64 | Unhealthy |
| Jun | 60 | Unhealthy |
| Jul | 54 | Poor |
| Aug | 48 | Poor |
| Sep | 47 | Poor |
| Oct | 49 | Poor |
| Nov | 48 | Poor |
| Dec | 43 | Poor |
Where is Kertosono?
Kertosono sits at 7.6°S, 112.1°E, 43 m above sea level, in Indonesia. The nearest listed city is Diwek, 14 km away.
Topography around Kertosono
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Kertosono.
Within 3 km, the terrain around Kertosono has only modest variations in elevation — a maximum elevation change of 13 m around an average of 42 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 248 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,305 m.
The land around Kertosono is covered by cropland (52%), trees (23%) and artificial surfaces (22%) within 3 km, cropland (55%) and trees (28%) within 16 km, and trees (49%) and cropland (37%) within 80 km.
Indonesia travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F
- 230 V · 50 Hz
- Prices
- ≈ 29% of US
- price level, 2025
- GDP per capita
- $5,060
- 2025
- Happiness
- 5.6 / 10
- World Happiness, 2025
- Safe drinking water
- 30%
- of population, 2024
- Homicide rate
- 0.3
- per 100k, 2022
- Road deaths
- 11.3
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Low
- EF EPI 471
- 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 Kertosono (-7.5833°, 112.1°, elevation 43 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.