Cổ Đô in Fall
In fall (September, October and November), Cổ Đô sees average daytime highs around 28°C and overnight lows near 22°C, with 407 mm of rain over about 38 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 32°C in early September to 23°C by late November. The sky is clear or mostly clear about 28% of the time across fall, and the air most often feels oppressive.
Fall is Cổ Đô's 2nd-best season to visit on our travel score. For the whole year in context, see Cổ Đô's year-round climate.
- Avg daytime high
- 28°C
- 2nd-warmest season
- Avg overnight low
- 22°C
- Rainfall
- 407 mm
- 38 wet days
- Avg wind
- 5 km/h
- Travel score
- 5.4
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Cổ Đô in Fall
Over the season highs ease from about 32°C in early September to 23°C by late November.
A typical fall day in Cổ Đô reaches about 28°C and drops to 22°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Cổ Đô
Once humidity and wind are folded in, fall brings about 40 days that feel above 32°C and 0 that feel at or below 0°C.
The story in fall is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Cổ Đô weather by month
How the three fall months (September, October and November) 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 Fall
The sky is clear or mostly clear about 28% of the time across fall.
Chance of precipitation in Fall
Cổ Đô gets around 407 mm of rain over 38 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 5 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 24 min in early September to 10 h 48 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 3.7 kWh/m².
Hazard calendar for Cổ Đô
In fall, 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 fall a good time to visit Cổ Đô?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a reasonable time to visit Cổ Đô for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Cổ Đô in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Cổ Đô sees daytime highs around 28°C and nights near 22°C. Pack light clothes and rain gear. About 38 days see rain.
UV index in Cổ Đô in Fall
Clear-sky midday UV across fall 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 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 Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall 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.