Cổ Đô in Summer
In summer (June, July and August), Cổ Đô sees average daytime highs around 33°C and overnight lows near 26°C, with 883 mm of rain over about 63 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 33°C. The sky is clear or mostly clear about 7% of the time across summer, and the air most often feels miserable.
Summer is Cổ Đô's weakest season of the year to visit on our travel score. For the whole year in context, see Cổ Đô's year-round climate.
- Avg daytime high
- 33°C
- warmest season of the year
- Avg overnight low
- 26°C
- Rainfall
- 883 mm
- 63 wet days
- Avg wind
- 5 km/h
- Travel score
- 2.6
- weakest season of the year
- Months
- Jun · Jul · Aug
Temperature in Cổ Đô in Summer
Across summer, daytime highs hold fairly steady around 33°C.
A typical summer day in Cổ Đô reaches about 33°C and drops to 26°C overnight. The warmest of the three months is June, the coolest August.
How summer really feels in Cổ Đô
Once humidity and wind are folded in, summer brings about 92 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.
Cổ Đô 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 | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 19° / 14° | 45 | 9.1 | 10.8 | 6.0 |
| Feb | 21° / 15° | 34 | 8.5 | 11.3 | 6.3 |
| Mar | 24° / 18° | 61 | 11.6 | 11.8 | 6.3 |
| Apr | 29° / 22° | 103 | 12.2 | 12.5 | 5.2 |
| May | 31° / 25° | 230 | 17.9 | 13 | 3.4 |
| Jun | 33° / 26° | 238 | 19.1 | 13.3 | 2.6 |
| Jul | 33° / 26° | 291 | 20.9 | 13.2 | 2.6 |
| Aug | 32° / 26° | 354 | 22.5 | 12.7 | 2.7 |
| Sep | 31° / 25° | 230 | 18.8 | 12.1 | 3.5 |
| Oct | 29° / 22° | 119 | 11.6 | 11.5 | 5.6 |
| Nov | 25° / 19° | 58 | 7.5 | 11 | 7.1 |
| Dec | 21° / 15° | 38 | 7.6 | 10.7 | 6.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 7% of the time across summer.
Chance of precipitation in Summer
Cổ Đô gets around 883 mm of rain over 63 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels miserable — 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 13 h 12 min in early June to 12 h 24 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 4.6 kWh/m².
Hazard calendar for Cổ Đô
In summer, Cổ Đô overlaps its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.
Cổ Đô sits in the Pacific typhoon belt; the season peaks July–October.
Cổ Đô's monsoon runs May–September, when most of the year's rain falls.
Is summer a good time to visit Cổ Đô?
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 Cổ Đô.
What to pack for Cổ Đô in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Cổ Đô sees daytime highs around 33°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 63 days see rain.
UV index in Cổ Đô 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 Cổ Đô peaks around June 20 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 20 at about 5 (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) | 6 | 7 | 8 | 6 | 8 | 12 | 11 | 11 | 6 | 7 | 5 | 6 |
| Level | High | High | Very high | High | Very high | Extreme | Extreme | Extreme | High | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 6 | High |
| Feb | 7 | High |
| Mar | 8 | Very high |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 12 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 6 | High |
| Oct | 7 | Very high |
| Nov | 5 | High |
| Dec | 6 | High |
Air quality in Cổ Đô 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 Cổ Đô is worst in April — around 98 µg/m³ PM2.5 (unhealthy), about 3.8× the cleanest month (July, 26 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) | 76 | 71 | 76 | 98 | 57 | 32 | 26 | 28 | 39 | 53 | 66 | 77 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Moderate | Moderate | Moderate | Poor | Poor | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 76 | Unhealthy |
| Feb | 71 | Unhealthy |
| Mar | 76 | Unhealthy |
| Apr | 98 | Unhealthy |
| May | 57 | Unhealthy |
| Jun | 32 | Moderate |
| Jul | 26 | Moderate |
| Aug | 28 | Moderate |
| Sep | 39 | Poor |
| Oct | 53 | Poor |
| Nov | 66 | Unhealthy |
| Dec | 77 | Unhealthy |
Where is Cổ Đô?
Cổ Đô sits at 21.3°N, 105.4°E, 17 m above sea level, in Vietnam. The nearest listed city is Việt Trì, 6.0 km away.
Topography around Cổ Đô
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Cổ Đô.
Within 3 km, the terrain around Cổ Đô has only modest variations in elevation — a maximum elevation change of 22 m around an average of 13 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 333 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,211 m.
The land around Cổ Đô is covered by cropland (39%) within 3 km, trees (42%) and cropland (33%) within 16 km, and trees (72%) within 80 km.
Vietnam travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B / C / F
- 220 V · 50 Hz
- Prices
- ≈ 29% of US
- price level, 2025
- GDP per capita
- $5,066
- 2025
- Happiness
- 6.4 / 10
- World Happiness, 2025
- Safe drinking water
- 59%
- of population, 2024
- Homicide rate
- 1.5
- per 100k, 2011
- Road deaths
- 30.6
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 500
- 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 Cổ Đô (21.2796°, 105.364°, elevation 17 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.