Yilan weather in May
In May, Yilan sees average daytime highs of 25°C and overnight lows near 21°C, with 297 mm of rain across 25.2 wet days and about 13.2 hours of daylight. It is the 5th-warmest and 6th-wettest month of the year here.
Highs climb over the month, from about 24°C in the first days to 27°C by the end. The sky is clear or mostly clear about 7% of the time in May, and the air most often feels oppressive.
Daylight stretches from about 12 h 54 min at the start of May to 13 h 24 min by month's end. Set against the rest of the year, May is Yilan's 8th-clearest and 10th-windiest month. For the whole year in context, see Yilan's year-round climate.
- Daytime high
- 25°
- 5th warmest
- Overnight low
- 21°
- 8th coldest
- Rainfall
- 297 mm
- 25.2 wet days
- Daylight
- 13 h 12 min
- 5:13 AM – 6:25 PM
- Cloud cover
- 80%
- 8th clearest
- Wind
- 6 km/h
- 10th windiest
- Solar energy
- 4.72 kWh/m²
- Travel score
- 4.3
- out of 10
Yilan is A county-administered city in Yilan County, Taiwan.
- Density
- 3,203/km²
- people per km²
- Founded
- 1945
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in May
Highs climb over the month, from about 24°C in the first days to 27°C by the end.
A typical May day in Yilan reaches about 25°C in the afternoon and slips back to 21°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 28°C. Set against its neighbours, May runs about 3°C warmer than April and about 3°C cooler than June.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 24 | 24 | 24 | 24 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 27 | 27 | 27 |
| Avg low (°C) | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 22 | 23 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 24 | 20 |
| 2 | 24 | 20 |
| 3 | 24 | 20 |
| 4 | 24 | 20 |
| 5 | 25 | 20 |
| 6 | 25 | 20 |
| 7 | 25 | 20 |
| 8 | 25 | 20 |
| 9 | 25 | 21 |
| 10 | 25 | 21 |
| 11 | 25 | 21 |
| 12 | 25 | 21 |
| 13 | 25 | 21 |
| 14 | 25 | 21 |
| 15 | 25 | 21 |
| 16 | 26 | 21 |
| 17 | 26 | 21 |
| 18 | 26 | 21 |
| 19 | 26 | 22 |
| 20 | 26 | 22 |
| 21 | 26 | 22 |
| 22 | 26 | 22 |
| 23 | 26 | 22 |
| 24 | 26 | 22 |
| 25 | 26 | 22 |
| 26 | 26 | 22 |
| 27 | 26 | 22 |
| 28 | 26 | 22 |
| 29 | 27 | 22 |
| 30 | 27 | 22 |
| 31 | 27 | 23 |
How May really feels in Yilan
Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Yilan weather by month
How May compares with the rest of the year at a glance. May is the 5th-warmest and 6th-wettest month here — the current month is highlighted below.
| 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 May
The sky is clear or mostly clear about 7% of the time in May.
Beyond those clear spells, partly cloudy skies cover about 11% of May, with mostly cloudy or overcast conditions the remaining 82%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 19 | 19 | 19 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 18 | 18 | 18 | 18 | 16 | 16 | 16 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 14 | 14 |
| Cloudier (%) | 81 | 81 | 81 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 82 | 82 | 82 | 82 | 84 | 84 | 84 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 86 | 86 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 19 | 81 |
| 2 | 19 | 81 |
| 3 | 19 | 81 |
| 4 | 20 | 80 |
| 5 | 20 | 80 |
| 6 | 20 | 80 |
| 7 | 20 | 80 |
| 8 | 20 | 80 |
| 9 | 20 | 80 |
| 10 | 20 | 80 |
| 11 | 20 | 80 |
| 12 | 20 | 80 |
| 13 | 20 | 80 |
| 14 | 20 | 80 |
| 15 | 20 | 80 |
| 16 | 18 | 82 |
| 17 | 18 | 82 |
| 18 | 18 | 82 |
| 19 | 18 | 82 |
| 20 | 16 | 84 |
| 21 | 16 | 84 |
| 22 | 16 | 84 |
| 23 | 15 | 85 |
| 24 | 15 | 85 |
| 25 | 15 | 85 |
| 26 | 15 | 85 |
| 27 | 15 | 85 |
| 28 | 15 | 85 |
| 29 | 15 | 85 |
| 30 | 14 | 86 |
| 31 | 14 | 86 |
Chance of precipitation in May
Yilan gets around 297 mm of rain over 25.2 wet days in May. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 80% and peaks near 85% on the wettest days. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 76 | 76 | 76 | 76 | 76 | 76 | 77 | 77 | 77 | 77 | 77 | 78 | 78 | 79 | 79 | 80 | 81 | 81 | 82 | 83 | 84 | 84 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 85 |
| Rain chance (%) | |
|---|---|
| 1 | 76 |
| 2 | 76 |
| 3 | 76 |
| 4 | 76 |
| 5 | 76 |
| 6 | 76 |
| 7 | 77 |
| 8 | 77 |
| 9 | 77 |
| 10 | 77 |
| 11 | 77 |
| 12 | 78 |
| 13 | 78 |
| 14 | 79 |
| 15 | 79 |
| 16 | 80 |
| 17 | 81 |
| 18 | 81 |
| 19 | 82 |
| 20 | 83 |
| 21 | 84 |
| 22 | 84 |
| 23 | 85 |
| 24 | 85 |
| 25 | 85 |
| 26 | 85 |
| 27 | 85 |
| 28 | 85 |
| 29 | 85 |
| 30 | 85 |
| 31 | 85 |
Humidity in May
Most of May feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, May lands in the oppressive band about 45% of days. Sticky, muggy-or-worse air turns up on roughly 80% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 4 | 4 | 4 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Comfortable (%) | 9 | 8 | 8 | 7 | 7 | 6 | 6 | 6 | 5 | 5 | 5 | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 |
| Humid (%) | 21 | 21 | 21 | 20 | 20 | 19 | 19 | 18 | 18 | 17 | 16 | 16 | 15 | 15 | 14 | 14 | 13 | 12 | 12 | 12 | 11 | 11 | 11 | 11 | 11 | 11 | 10 | 10 | 9 | 9 | 8 |
| Muggy (%) | 45 | 44 | 43 | 42 | 41 | 41 | 40 | 39 | 38 | 38 | 37 | 36 | 36 | 35 | 35 | 34 | 34 | 33 | 32 | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 |
| Oppressive (%) | 21 | 23 | 25 | 27 | 29 | 31 | 33 | 35 | 37 | 39 | 41 | 42 | 44 | 45 | 46 | 48 | 49 | 51 | 51 | 52 | 54 | 54 | 55 | 56 | 56 | 57 | 59 | 60 | 61 | 62 | 63 |
| Miserable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 5 | 5 | 6 | 6 | 7 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 4 | 9 | 21 | 45 | 21 | 0 |
| 2 | 4 | 8 | 21 | 44 | 23 | 0 |
| 3 | 4 | 8 | 21 | 43 | 25 | 0 |
| 4 | 3 | 7 | 20 | 42 | 27 | 0 |
| 5 | 3 | 7 | 20 | 41 | 29 | 0 |
| 6 | 3 | 6 | 19 | 41 | 31 | 0 |
| 7 | 2 | 6 | 19 | 40 | 33 | 0 |
| 8 | 2 | 6 | 18 | 39 | 35 | 0 |
| 9 | 2 | 5 | 18 | 38 | 37 | 0 |
| 10 | 2 | 5 | 17 | 38 | 39 | 0 |
| 11 | 1 | 5 | 16 | 37 | 41 | 0 |
| 12 | 1 | 4 | 16 | 36 | 42 | 0 |
| 13 | 1 | 4 | 15 | 36 | 44 | 0 |
| 14 | 1 | 4 | 15 | 35 | 45 | 0 |
| 15 | 1 | 3 | 14 | 35 | 46 | 1 |
| 16 | 0 | 3 | 14 | 34 | 48 | 1 |
| 17 | 0 | 3 | 13 | 34 | 49 | 1 |
| 18 | 0 | 3 | 12 | 33 | 51 | 1 |
| 19 | 0 | 3 | 12 | 32 | 51 | 2 |
| 20 | 0 | 3 | 12 | 31 | 52 | 2 |
| 21 | 0 | 3 | 11 | 30 | 54 | 2 |
| 22 | 0 | 3 | 11 | 29 | 54 | 3 |
| 23 | 0 | 3 | 11 | 28 | 55 | 3 |
| 24 | 0 | 3 | 11 | 27 | 56 | 3 |
| 25 | 0 | 3 | 11 | 26 | 56 | 4 |
| 26 | 0 | 3 | 11 | 25 | 57 | 4 |
| 27 | 0 | 2 | 10 | 24 | 59 | 5 |
| 28 | 0 | 2 | 10 | 23 | 60 | 5 |
| 29 | 0 | 2 | 9 | 22 | 61 | 6 |
| 30 | 0 | 2 | 9 | 21 | 62 | 6 |
| 31 | 0 | 2 | 8 | 20 | 63 | 7 |
Wind in May
Winds average 6 km/h in May.
Across May, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 6 | calm |
| 2 | 6 | calm |
| 3 | 6 | calm |
| 4 | 6 | calm |
| 5 | 6 | calm |
| 6 | 6 | calm |
| 7 | 6 | calm |
| 8 | 6 | calm |
| 9 | 6 | calm |
| 10 | 6 | calm |
| 11 | 6 | calm |
| 12 | 6 | calm |
| 13 | 6 | calm |
| 14 | 6 | calm |
| 15 | 6 | calm |
| 16 | 6 | calm |
| 17 | 6 | calm |
| 18 | 6 | calm |
| 19 | 6 | calm |
| 20 | 6 | calm |
| 21 | 6 | calm |
| 22 | 6 | calm |
| 23 | 6 | calm |
| 24 | 6 | calm |
| 25 | 6 | calm |
| 26 | 6 | calm |
| 27 | 6 | calm |
| 28 | 6 | calm |
| 29 | 6 | calm |
| 30 | 6 | calm |
| 31 | 5 | calm |
Sunrise & sunset in May
Daylight runs from about 12 h 54 min at the start of May to 13 h 24 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 30 minutes over May. Sunrise moves from 5:23 AM to 5:08 AM, and sunset from 6:18 PM to 6:33 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.9 | 12.9 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.2 | 13.2 | 13.2 | 13.2 | 13.2 | 13.2 | 13.3 | 13.3 | 13.3 | 13.3 | 13.3 | 13.3 | 13.3 | 13.4 | 13.4 | 13.4 | 13.4 | 13.4 |
| Sunrise (AM) | 5:23 | 5:22 | 5:21 | 5:21 | 5:20 | 5:19 | 5:18 | 5:18 | 5:17 | 5:17 | 5:16 | 5:15 | 5:15 | 5:14 | 5:14 | 5:13 | 5:13 | 5:12 | 5:12 | 5:11 | 5:11 | 5:11 | 5:10 | 5:10 | 5:10 | 5:09 | 5:09 | 5:09 | 5:09 | 5:08 | 5:08 |
| Sunset (PM) | 6:18 | 6:18 | 6:19 | 6:19 | 6:20 | 6:20 | 6:21 | 6:21 | 6:22 | 6:22 | 6:23 | 6:23 | 6:24 | 6:24 | 6:25 | 6:25 | 6:26 | 6:26 | 6:27 | 6:27 | 6:28 | 6:28 | 6:29 | 6:29 | 6:30 | 6:30 | 6:31 | 6:31 | 6:32 | 6:32 | 6:33 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.9 | 5:23 | 6:18 |
| 2 | 12.9 | 5:22 | 6:18 |
| 3 | 13.0 | 5:21 | 6:19 |
| 4 | 13.0 | 5:21 | 6:19 |
| 5 | 13.0 | 5:20 | 6:20 |
| 6 | 13.0 | 5:19 | 6:20 |
| 7 | 13.0 | 5:18 | 6:21 |
| 8 | 13.1 | 5:18 | 6:21 |
| 9 | 13.1 | 5:17 | 6:22 |
| 10 | 13.1 | 5:17 | 6:22 |
| 11 | 13.1 | 5:16 | 6:23 |
| 12 | 13.1 | 5:15 | 6:23 |
| 13 | 13.1 | 5:15 | 6:24 |
| 14 | 13.2 | 5:14 | 6:24 |
| 15 | 13.2 | 5:14 | 6:25 |
| 16 | 13.2 | 5:13 | 6:25 |
| 17 | 13.2 | 5:13 | 6:26 |
| 18 | 13.2 | 5:12 | 6:26 |
| 19 | 13.2 | 5:12 | 6:27 |
| 20 | 13.3 | 5:11 | 6:27 |
| 21 | 13.3 | 5:11 | 6:28 |
| 22 | 13.3 | 5:11 | 6:28 |
| 23 | 13.3 | 5:10 | 6:29 |
| 24 | 13.3 | 5:10 | 6:29 |
| 25 | 13.3 | 5:10 | 6:30 |
| 26 | 13.3 | 5:09 | 6:30 |
| 27 | 13.4 | 5:09 | 6:31 |
| 28 | 13.4 | 5:09 | 6:31 |
| 29 | 13.4 | 5:09 | 6:32 |
| 30 | 13.4 | 5:08 | 6:32 |
| 31 | 13.4 | 5:08 | 6:33 |
Solar energy in May
Average shortwave solar energy reaching the ground each day in May, about 4.72 kWh/m².
For context, solar energy here swings from a low near 2.07 kWh/m² to a high of 5.81 kWh/m² in July across the year — May's 4.72 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.6 | 4.6 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.7 | 4.8 | 4.8 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.6 | Bright |
| 2 | 4.6 | Bright |
| 3 | 4.7 | Bright |
| 4 | 4.7 | Bright |
| 5 | 4.7 | Bright |
| 6 | 4.7 | Bright |
| 7 | 4.7 | Bright |
| 8 | 4.7 | Bright |
| 9 | 4.8 | Bright |
| 10 | 4.8 | Bright |
| 11 | 4.8 | Bright |
| 12 | 4.8 | Bright |
| 13 | 4.8 | Bright |
| 14 | 4.8 | Bright |
| 15 | 4.8 | Bright |
| 16 | 4.7 | Bright |
| 17 | 4.7 | Bright |
| 18 | 4.7 | Bright |
| 19 | 4.7 | Bright |
| 20 | 4.7 | Bright |
| 21 | 4.7 | Bright |
| 22 | 4.7 | Bright |
| 23 | 4.7 | Bright |
| 24 | 4.7 | Bright |
| 25 | 4.7 | Bright |
| 26 | 4.7 | Bright |
| 27 | 4.7 | Bright |
| 28 | 4.7 | Bright |
| 29 | 4.7 | Bright |
| 30 | 4.8 | Bright |
| 31 | 4.8 | Bright |
Hazard calendar for Yilan
In May, Yilan sits inside 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 May a good time to visit Yilan?
Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
May is a reasonable time to visit Yilan for sightseeing.
What to pack for Yilan in May
From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In May, Yilan sees daytime highs around 25°C and nights near 21°C. Pack rain gear. Worth having: light clothes and sun protection. About 25 days see rain.
Sea temperature near Yilan in May
The nearest coast averages about 26°C in May — 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 May
Clear-sky midday UV in May peaks around 10 (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 May
Average fine-particle pollution (PM2.5) through the year — so you can see where May 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).