La Unión in Summer
In summer (December, January and February), La Unión sees average daytime highs around 21°C and overnight lows near 10°C, with 141 mm of rain over about 19 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 19°C in early December to 22°C by late February. The sky is clear or mostly clear about 39% of the time across summer, and the air most often feels dry.
Summer is La Unión's best season of the year to visit on our travel score. For the whole year in context, see La Unión's year-round climate.
- Avg daytime high
- 21°C
- warmest season of the year
- Avg overnight low
- 10°C
- Rainfall
- 141 mm
- 19 wet days
- Avg wind
- 11 km/h
- Travel score
- 7.2
- best season of the year
- Months
- Dec · Jan · Feb
Temperature in La Unión in Summer
Over the season highs climb from about 19°C in early December to 22°C by late February.
A typical summer day in La Unión reaches about 21°C and drops to 10°C overnight. The warmest of the three months is February, the coolest December.
La Unión 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 | 22° / 10° | 36 | 6 | 14.5 | 7.5 |
| Feb | 22° / 10° | 41 | 5.1 | 13.6 | 7.6 |
| Mar | 20° / 9° | 63 | 7.6 | 12.3 | 6.7 |
| Apr | 16° / 7° | 109 | 10.6 | 11 | 4.9 |
| May | 13° / 6° | 189 | 15.4 | 9.8 | 3.1 |
| Jun | 11° / 4° | 254 | 18.3 | 9.2 | 2.0 |
| Jul | 10° / 4° | 229 | 17.8 | 9.4 | 1.9 |
| Aug | 11° / 4° | 210 | 17.8 | 10.4 | 2.3 |
| Sep | 13° / 5° | 125 | 13.5 | 11.7 | 3.4 |
| Oct | 15° / 6° | 110 | 13.4 | 13.1 | 4.3 |
| Nov | 17° / 8° | 74 | 9.9 | 14.2 | 5.5 |
| Dec | 20° / 9° | 64 | 8 | 14.8 | 6.6 |
Cloud cover in Summer
The sky is clear or mostly clear about 39% of the time across summer.
Chance of precipitation in Summer
La Unión gets around 141 mm of rain over 19 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 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 42 min in early December to 13 hours 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 6.7 kWh/m².
Hazard calendar for La Unión
None of La Unión's seasonal hazards peak in summer. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
La Unión's rainy season runs May–September, when most of the year's rain falls.
Is summer a good time to visit La Unión?
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 La Unión for general sightseeing.
What to pack for La Unión in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, La Unión sees daytime highs around 21°C and nights near 10°C. Pack sun protection. Worth having: light clothes and rain gear. About 19 days see rain.
Sea temperature near La Unión in Summer
The nearest coast averages about 14°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 66 km away) is warmest in January at about 14°C and coldest in August near 11°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) | 14 | 14 | 14 | 13 | 13 | 12 | 11 | 11 | 11 | 12 | 13 | 14 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 14 | Bracing |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 13 | Bracing |
| May | 13 | Bracing |
| Jun | 12 | Bracing |
| Jul | 11 | Bracing |
| Aug | 11 | Bracing |
| Sep | 11 | Bracing |
| Oct | 12 | Bracing |
| Nov | 13 | Bracing |
| Dec | 14 | Bracing |
UV index in La Unión in Summer
Clear-sky midday UV across summer averages around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in La Unión peaks around December 20 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 18 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) | 11 | 11 | 7 | 5 | 2 | 2 | 2 | 3 | 4 | 7 | 9 | 12 |
| Level | Extreme | Extreme | Very high | Moderate | Moderate | Low | Low | Moderate | Moderate | High | Very high | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 11 | Extreme |
| Feb | 11 | Extreme |
| Mar | 7 | Very high |
| Apr | 5 | Moderate |
| May | 2 | Moderate |
| Jun | 2 | Low |
| Jul | 2 | Low |
| Aug | 3 | Moderate |
| Sep | 4 | Moderate |
| Oct | 7 | High |
| Nov | 9 | Very high |
| Dec | 12 | Extreme |
Air quality in La Unión 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 La Unión is worst in March — around 36 µg/m³ PM2.5 (poor), about 1.7× the cleanest month (February, 22 µg/m³).
Seasonal pattern from CAMS reanalysis, scaled to La Unión's WHO annual average of 29.9 µg/m³.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 24 | 22 | 36 | 36 | 28 | 26 | 27 | 33 | 36 | 33 | 31 | 27 |
| Level | Moderate | Moderate | Poor | Poor | Moderate | Moderate | Moderate | Moderate | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 24 | Moderate |
| Feb | 22 | Moderate |
| Mar | 36 | Poor |
| Apr | 36 | Poor |
| May | 28 | Moderate |
| Jun | 26 | Moderate |
| Jul | 27 | Moderate |
| Aug | 33 | Moderate |
| Sep | 36 | Poor |
| Oct | 33 | Moderate |
| Nov | 31 | Moderate |
| Dec | 27 | Moderate |
Where is La Unión?
La Unión sits at 40.3°S, 73.1°W, 32 m above sea level, in Chile. The nearest listed city is Río Bueno, 12 km away.
Topography around La Unión
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of La Unión.
Within 3 km, the terrain around La Unión has only modest variations in elevation — a maximum elevation change of 80 m around an average of 49 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 528 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,782 m.
The land around La Unión is covered by cropland (41%), trees (25%) and grassland (20%) within 3 km, trees (44%), cropland (29%) and grassland (25%) within 16 km, and trees (51%) and grassland (21%) within 80 km.
Chile travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F / L
- 220 V · 50 Hz
- Prices
- ≈ 48% of US
- price level, 2025
- GDP per capita
- $17,995
- 2025
- Happiness
- 6.3 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 6.3
- per 100k, 2023
- Road deaths
- 14.9
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 517
- 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 La Unión (-40.2931°, -73.0817°, elevation 32 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.