Yilan in Fall
In fall (September, October and November), Yilan sees average daytime highs around 24°C and overnight lows near 21°C, with 1067 mm of rain over about 63 wet days across the season. It is the 2nd-warmest season and the wettest season of the year.
Over the season highs ease from about 29°C in early September to 20°C by late November. The sky is clear or mostly clear about 12% of the time across fall, and the air most often feels oppressive.
Fall is Yilan's best season of the year to visit on our travel score. For the whole year in context, see Yilan's year-round climate.
- Avg daytime high
- 24°C
- 2nd-warmest season
- Avg overnight low
- 21°C
- Rainfall
- 1067 mm
- 63 wet days
- Avg wind
- 9 km/h
- Travel score
- 4.7
- best season of the year
- Months
- Sep · Oct · Nov
Temperature in Yilan in Fall
Over the season highs ease from about 29°C in early September to 20°C by late November.
A typical fall day in Yilan reaches about 24°C and drops to 21°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Yilan
Once humidity and wind are folded in, fall brings about 1 day 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.
Yilan 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 | 17° / 13° | 190 | 22 | 10.6 | 3.6 |
| Feb | 17° / 13° | 164 | 19.7 | 11.1 | 3.9 |
| Mar | 19° / 15° | 152 | 19.9 | 11.8 | 4.6 |
| Apr | 22° / 18° | 185 | 20.8 | 12.6 | 4.8 |
| May | 25° / 21° | 297 | 25.2 | 13.2 | 4.3 |
| Jun | 28° / 24° | 319 | 25.3 | 13.5 | 3.6 |
| Jul | 30° / 25° | 271 | 22.3 | 13.4 | 3.7 |
| Aug | 29° / 25° | 329 | 22.9 | 12.9 | 3.7 |
| Sep | 27° / 24° | 336 | 20.5 | 12.2 | 4.6 |
| Oct | 24° / 21° | 394 | 21.6 | 11.4 | 4.9 |
| Nov | 21° / 18° | 336 | 21 | 10.8 | 4.6 |
| Dec | 18° / 14° | 244 | 21.7 | 10.5 | 4.1 |
Cloud cover in Fall
The sky is clear or mostly clear about 12% of the time across fall.
Chance of precipitation in Fall
Yilan gets around 1067 mm of rain over 63 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 9 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 30 min in early September to 10 h 36 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 3.5 kWh/m².
Hazard calendar for Yilan
In fall, Yilan overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Yilan sits in the Pacific typhoon belt; the season peaks July–October.
Is fall a good time to visit Yilan?
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 Yilan for sightseeing.
What to pack for Yilan in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Yilan sees daytime highs around 24°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 63 days see rain.
Sea temperature near Yilan in Fall
The nearest coast averages about 26°C across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 18 km away) is warmest in August at about 28°C and coldest in January near 22°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 22 | 22 | 23 | 24 | 26 | 27 | 28 | 28 | 28 | 26 | 25 | 23 |
| Comfort | Refreshing | Refreshing | Refreshing | Warm | Warm | Warm | Tropical | Tropical | Warm | Warm | Warm | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 22 | Refreshing |
| Feb | 22 | Refreshing |
| Mar | 23 | Refreshing |
| Apr | 24 | Warm |
| May | 26 | Warm |
| Jun | 27 | Warm |
| Jul | 28 | Tropical |
| Aug | 28 | Tropical |
| Sep | 28 | Warm |
| Oct | 26 | Warm |
| Nov | 25 | Warm |
| Dec | 23 | Refreshing |
UV index in Yilan in Fall
Clear-sky midday UV across fall averages around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Yilan peaks around July 14 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 | 8 | 9 | 7 | 10 | 11 | 12 | 10 | 11 | 8 | 7 | 5 |
| Level | High | Very high | Very high | High | Extreme | Extreme | Extreme | Very high | Extreme | Very high | High | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 6 | High |
| Feb | 8 | Very high |
| Mar | 9 | Very high |
| Apr | 7 | High |
| May | 10 | Extreme |
| Jun | 11 | Extreme |
| Jul | 12 | Extreme |
| Aug | 10 | Very high |
| Sep | 11 | Extreme |
| Oct | 8 | Very high |
| Nov | 7 | High |
| Dec | 5 | Moderate |
Air quality in Yilan 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 Yilan is worst in April — around 52 µg/m³ PM2.5 (poor), about 2.1× the cleanest month (October, 25 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) | 38 | 43 | 51 | 52 | 44 | 41 | 32 | 32 | 30 | 25 | 32 | 32 |
| Level | Poor | Poor | Poor | Poor | Poor | Poor | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 38 | Poor |
| Feb | 43 | Poor |
| Mar | 51 | Poor |
| Apr | 52 | Poor |
| May | 44 | Poor |
| Jun | 41 | Poor |
| Jul | 32 | Moderate |
| Aug | 32 | Moderate |
| Sep | 30 | Moderate |
| Oct | 25 | Moderate |
| Nov | 32 | Moderate |
| Dec | 32 | Moderate |
Where is Yilan?
Yilan sits at 24.8°N, 121.8°E, 15 m above sea level, in Taiwan. The nearest listed city is Xizhi, 36 km away.
Topography around Yilan
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Yilan.
Within 3 km, the terrain around Yilan has only modest variations in elevation — a maximum elevation change of 33 m around an average of 9 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,413 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,839 m.
The land around Yilan is covered by cropland (40%), artificial surfaces (35%) and trees (21%) within 3 km, trees (50%) and water (23%) within 16 km, and trees (47%) and water (46%) within 80 km.
Taiwan travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 110 / 220 V · 60 Hz
- Happiness
- 6.7 / 10
- World Happiness, 2025
- 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 Yilan (24.757°, 121.753°, elevation 15 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.