Karatsu weather in April
In April, Karatsu sees average daytime highs of 17°C and overnight lows near 12°C, with 134 mm of rain across 11 wet days and about 12.8 hours of daylight. It is the 7th-warmest and 6th-wettest month of the year here.
Highs climb over the month, from about 15°C in the first days to 19°C by the end. The sky is clear or mostly clear about 35% of the time in April, and the air most often feels dry.
Daylight stretches from about 12 h 18 min at the start of April to 13 h 18 min by month's end. Set against the rest of the year, April is Karatsu's 4th-clearest and 8th-windiest month. For the whole year in context, see Karatsu's year-round climate.
- Daytime high
- 17°
- 7th warmest
- Overnight low
- 12°
- 5th coldest
- Rainfall
- 134 mm
- 11 wet days
- Daylight
- 12 h 48 min
- 5:55 AM – 6:45 PM
- Cloud cover
- 59%
- 4th clearest
- Wind
- 13 km/h
- 8th windiest
- Solar energy
- 5.06 kWh/m²
- Travel score
- 5.3
- out of 10
Karatsu is city in Saga Prefecture, Japan.
- Density
- 241/km²
- people per km²
- Founded
- 2005
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in April
Highs climb over the month, from about 15°C in the first days to 19°C by the end.
A typical April day in Karatsu reaches about 17°C in the afternoon and slips back to 12°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 20°C. Set against its neighbours, April runs about 4°C warmer than March and about 4°C cooler than May.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 15 | 15 | 15 | 15 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 17 | 17 | 17 | 18 | 18 | 18 | 18 | 18 | 18 | 19 | 19 | 19 | 19 | 19 | 19 |
| Avg low (°C) | 10 | 10 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 14 | 14 | 14 | 14 | 14 | 14 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 15 | 10 |
| 2 | 15 | 10 |
| 3 | 15 | 11 |
| 4 | 15 | 11 |
| 5 | 16 | 11 |
| 6 | 16 | 11 |
| 7 | 16 | 11 |
| 8 | 16 | 11 |
| 9 | 16 | 11 |
| 10 | 16 | 11 |
| 11 | 16 | 12 |
| 12 | 17 | 12 |
| 13 | 17 | 12 |
| 14 | 17 | 12 |
| 15 | 17 | 12 |
| 16 | 17 | 12 |
| 17 | 17 | 12 |
| 18 | 17 | 13 |
| 19 | 18 | 13 |
| 20 | 18 | 13 |
| 21 | 18 | 13 |
| 22 | 18 | 13 |
| 23 | 18 | 13 |
| 24 | 18 | 13 |
| 25 | 19 | 14 |
| 26 | 19 | 14 |
| 27 | 19 | 14 |
| 28 | 19 | 14 |
| 29 | 19 | 14 |
| 30 | 19 | 14 |
How April really feels in Karatsu
Once humidity and wind are folded in, April 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.
April sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Karatsu weather by month
How April compares with the rest of the year at a glance. April is the 7th-warmest and 6th-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 9° / 6° | 77 | 11.8 | 1.2 | 10 | 1.9 |
| Feb | 10° / 6° | 78 | 10.3 | 0.8 | 10.8 | 2.2 |
| Mar | 13° / 8° | 124 | 11.6 | 0.2 | 11.7 | 3.5 |
| Apr | 17° / 12° | 134 | 11 | 0 | 12.8 | 5.3 |
| May | 21° / 16° | 143 | 10.3 | 0 | 13.7 | 6.4 |
| Jun | 24° / 20° | 277 | 14.7 | 0 | 14.2 | 5.8 |
| Jul | 28° / 24° | 260 | 15.4 | 0 | 14 | 5.1 |
| Aug | 29° / 26° | 162 | 13.7 | 0 | 13.2 | 4.9 |
| Sep | 26° / 22° | 179 | 12.6 | 0 | 12.2 | 6.2 |
| Oct | 22° / 18° | 103 | 8.1 | 0 | 11.2 | 7.1 |
| Nov | 17° / 13° | 95 | 9.3 | 0 | 10.3 | 5.5 |
| Dec | 12° / 8° | 81 | 11.1 | 0.3 | 9.8 | 3.0 |
Cloud cover in April
The sky is clear or mostly clear about 35% of the time in April.
Beyond those clear spells, partly cloudy skies cover about 12% of April, with mostly cloudy or overcast conditions the remaining 54%.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 47 | 47 | 46 | 45 | 46 | 46 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 46 | 46 | 46 | 47 | 47 | 48 | 48 | 47 | 47 | 47 | 48 | 47 | 47 | 47 |
| Cloudier (%) | 53 | 53 | 54 | 55 | 54 | 54 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 54 | 54 | 54 | 53 | 53 | 52 | 52 | 53 | 53 | 53 | 52 | 53 | 53 | 53 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 47 | 53 |
| 2 | 47 | 53 |
| 3 | 46 | 54 |
| 4 | 45 | 55 |
| 5 | 46 | 54 |
| 6 | 46 | 54 |
| 7 | 45 | 55 |
| 8 | 45 | 55 |
| 9 | 45 | 55 |
| 10 | 45 | 55 |
| 11 | 45 | 55 |
| 12 | 45 | 55 |
| 13 | 45 | 55 |
| 14 | 45 | 55 |
| 15 | 45 | 55 |
| 16 | 45 | 55 |
| 17 | 46 | 54 |
| 18 | 46 | 54 |
| 19 | 46 | 54 |
| 20 | 47 | 53 |
| 21 | 47 | 53 |
| 22 | 48 | 52 |
| 23 | 48 | 52 |
| 24 | 47 | 53 |
| 25 | 47 | 53 |
| 26 | 47 | 53 |
| 27 | 48 | 52 |
| 28 | 47 | 53 |
| 29 | 47 | 53 |
| 30 | 47 | 53 |
Chance of precipitation in April
Karatsu gets around 134 mm of rain over 11 wet days in April. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 36% and peaks near 38% on the wettest days.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 37 | 37 | 37 | 37 | 38 | 38 | 38 | 38 | 38 | 37 | 37 | 37 | 37 | 37 | 36 | 36 | 36 | 35 | 35 | 34 | 34 |
| Rain chance (%) | |
|---|---|
| 1 | 36 |
| 2 | 36 |
| 3 | 36 |
| 4 | 36 |
| 5 | 36 |
| 6 | 36 |
| 7 | 36 |
| 8 | 36 |
| 9 | 36 |
| 10 | 37 |
| 11 | 37 |
| 12 | 37 |
| 13 | 37 |
| 14 | 38 |
| 15 | 38 |
| 16 | 38 |
| 17 | 38 |
| 18 | 38 |
| 19 | 37 |
| 20 | 37 |
| 21 | 37 |
| 22 | 37 |
| 23 | 37 |
| 24 | 36 |
| 25 | 36 |
| 26 | 36 |
| 27 | 35 |
| 28 | 35 |
| 29 | 34 |
| 30 | 34 |
Humidity in April
Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, April lands in the dry band about 77% of days. It rarely turns muggy — the humid and sticky bands barely register.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 91 | 91 | 90 | 89 | 89 | 87 | 87 | 86 | 86 | 85 | 85 | 84 | 82 | 81 | 80 | 80 | 78 | 77 | 76 | 74 | 72 | 69 | 67 | 65 | 62 | 60 | 59 | 57 | 54 | 53 |
| Comfortable (%) | 8 | 8 | 9 | 10 | 10 | 11 | 11 | 12 | 12 | 13 | 13 | 14 | 15 | 16 | 17 | 17 | 18 | 19 | 20 | 21 | 23 | 24 | 26 | 27 | 29 | 30 | 31 | 32 | 33 | 33 |
| Humid (%) | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 5 | 6 | 6 | 7 | 8 | 9 | 9 | 10 | 11 | 12 |
| Muggy (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | |
|---|---|---|---|---|
| 1 | 91 | 8 | 1 | 0 |
| 2 | 91 | 8 | 1 | 0 |
| 3 | 90 | 9 | 1 | 0 |
| 4 | 89 | 10 | 1 | 0 |
| 5 | 89 | 10 | 1 | 0 |
| 6 | 87 | 11 | 2 | 0 |
| 7 | 87 | 11 | 2 | 0 |
| 8 | 86 | 12 | 2 | 0 |
| 9 | 86 | 12 | 2 | 0 |
| 10 | 85 | 13 | 2 | 0 |
| 11 | 85 | 13 | 2 | 0 |
| 12 | 84 | 14 | 2 | 0 |
| 13 | 82 | 15 | 3 | 0 |
| 14 | 81 | 16 | 3 | 0 |
| 15 | 80 | 17 | 3 | 0 |
| 16 | 80 | 17 | 3 | 0 |
| 17 | 78 | 18 | 4 | 0 |
| 18 | 77 | 19 | 4 | 0 |
| 19 | 76 | 20 | 4 | 0 |
| 20 | 74 | 21 | 5 | 0 |
| 21 | 72 | 23 | 5 | 0 |
| 22 | 69 | 24 | 6 | 1 |
| 23 | 67 | 26 | 6 | 1 |
| 24 | 65 | 27 | 7 | 1 |
| 25 | 62 | 29 | 8 | 1 |
| 26 | 60 | 30 | 9 | 1 |
| 27 | 59 | 31 | 9 | 1 |
| 28 | 57 | 32 | 10 | 1 |
| 29 | 54 | 33 | 11 | 2 |
| 30 | 53 | 33 | 12 | 2 |
Wind in April
Winds average 13 km/h in April.
Across April, daily wind ranges from about 13 km/h on the calmest days to 14 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 14 | light breeze |
| 2 | 14 | light breeze |
| 3 | 14 | light breeze |
| 4 | 14 | light breeze |
| 5 | 14 | light breeze |
| 6 | 14 | light breeze |
| 7 | 14 | light breeze |
| 8 | 14 | light breeze |
| 9 | 14 | light breeze |
| 10 | 14 | light breeze |
| 11 | 14 | light breeze |
| 12 | 14 | light breeze |
| 13 | 14 | light breeze |
| 14 | 14 | light breeze |
| 15 | 14 | light breeze |
| 16 | 13 | light breeze |
| 17 | 13 | light breeze |
| 18 | 13 | light breeze |
| 19 | 13 | light breeze |
| 20 | 13 | light breeze |
| 21 | 13 | light breeze |
| 22 | 13 | light breeze |
| 23 | 13 | light breeze |
| 24 | 13 | light breeze |
| 25 | 13 | light breeze |
| 26 | 13 | light breeze |
| 27 | 13 | light breeze |
| 28 | 13 | light breeze |
| 29 | 13 | light breeze |
| 30 | 13 | light breeze |
Sunrise & sunset in April
Daylight runs from about 12 h 18 min at the start of April to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 60 minutes over April. Sunrise moves from 6:15 AM to 5:39 AM, and sunset from 6:34 PM to 6:56 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.3 | 12.3 | 12.4 | 12.4 | 12.5 | 12.5 | 12.5 | 12.6 | 12.6 | 12.6 | 12.7 | 12.7 | 12.7 | 12.8 | 12.8 | 12.8 | 12.9 | 12.9 | 12.9 | 13.0 | 13.0 | 13.0 | 13.1 | 13.1 | 13.1 | 13.2 | 13.2 | 13.2 | 13.3 | 13.3 |
| Sunrise (AM) | 6:15 | 6:14 | 6:13 | 6:11 | 6:10 | 6:09 | 6:07 | 6:06 | 6:05 | 6:03 | 6:02 | 6:01 | 5:59 | 5:58 | 5:57 | 5:55 | 5:54 | 5:53 | 5:52 | 5:50 | 5:49 | 5:48 | 5:47 | 5:46 | 5:45 | 5:43 | 5:42 | 5:41 | 5:40 | 5:39 |
| Sunset (PM) | 6:34 | 6:35 | 6:36 | 6:36 | 6:37 | 6:38 | 6:39 | 6:39 | 6:40 | 6:41 | 6:41 | 6:42 | 6:43 | 6:44 | 6:44 | 6:45 | 6:46 | 6:47 | 6:47 | 6:48 | 6:49 | 6:50 | 6:51 | 6:51 | 6:52 | 6:53 | 6:54 | 6:54 | 6:55 | 6:56 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.3 | 6:15 | 6:34 |
| 2 | 12.3 | 6:14 | 6:35 |
| 3 | 12.4 | 6:13 | 6:36 |
| 4 | 12.4 | 6:11 | 6:36 |
| 5 | 12.5 | 6:10 | 6:37 |
| 6 | 12.5 | 6:09 | 6:38 |
| 7 | 12.5 | 6:07 | 6:39 |
| 8 | 12.6 | 6:06 | 6:39 |
| 9 | 12.6 | 6:05 | 6:40 |
| 10 | 12.6 | 6:03 | 6:41 |
| 11 | 12.7 | 6:02 | 6:41 |
| 12 | 12.7 | 6:01 | 6:42 |
| 13 | 12.7 | 5:59 | 6:43 |
| 14 | 12.8 | 5:58 | 6:44 |
| 15 | 12.8 | 5:57 | 6:44 |
| 16 | 12.8 | 5:55 | 6:45 |
| 17 | 12.9 | 5:54 | 6:46 |
| 18 | 12.9 | 5:53 | 6:47 |
| 19 | 12.9 | 5:52 | 6:47 |
| 20 | 13.0 | 5:50 | 6:48 |
| 21 | 13.0 | 5:49 | 6:49 |
| 22 | 13.0 | 5:48 | 6:50 |
| 23 | 13.1 | 5:47 | 6:51 |
| 24 | 13.1 | 5:46 | 6:51 |
| 25 | 13.1 | 5:45 | 6:52 |
| 26 | 13.2 | 5:43 | 6:53 |
| 27 | 13.2 | 5:42 | 6:54 |
| 28 | 13.2 | 5:41 | 6:54 |
| 29 | 13.3 | 5:40 | 6:55 |
| 30 | 13.3 | 5:39 | 6:56 |
Solar energy in April
Average shortwave solar energy reaching the ground each day in April, about 5.06 kWh/m².
For context, solar energy here swings from a low near 2.14 kWh/m² to a high of 5.41 kWh/m² in May across the year — April's 5.06 kWh/m² sits near the top of that range.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.7 | 4.7 | 4.8 | 4.8 | 4.8 | 4.9 | 4.9 | 4.9 | 4.9 | 4.9 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.2 | 5.2 | 5.2 | 5.2 | 5.2 | 5.2 | 5.3 | 5.3 | 5.3 |
| 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 |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.7 | Bright |
| 2 | 4.7 | Bright |
| 3 | 4.8 | Bright |
| 4 | 4.8 | Bright |
| 5 | 4.8 | Bright |
| 6 | 4.9 | Bright |
| 7 | 4.9 | Bright |
| 8 | 4.9 | Bright |
| 9 | 4.9 | Bright |
| 10 | 4.9 | Bright |
| 11 | 5.0 | Bright |
| 12 | 5.0 | Bright |
| 13 | 5.0 | Bright |
| 14 | 5.0 | Bright |
| 15 | 5.0 | Bright |
| 16 | 5.0 | Bright |
| 17 | 5.1 | Bright |
| 18 | 5.1 | Bright |
| 19 | 5.1 | Bright |
| 20 | 5.1 | Bright |
| 21 | 5.1 | Bright |
| 22 | 5.2 | Bright |
| 23 | 5.2 | Bright |
| 24 | 5.2 | Bright |
| 25 | 5.2 | Bright |
| 26 | 5.2 | Bright |
| 27 | 5.2 | Bright |
| 28 | 5.3 | Bright |
| 29 | 5.3 | Bright |
| 30 | 5.3 | Bright |
Hazard calendar for Karatsu
In April, Karatsu sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Karatsu sits in the Pacific typhoon belt; the season peaks July–October.
Karatsu's rainy season runs April–September, when most of the year's rain falls.
Is April a good time to visit Karatsu?
Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
April is a reasonable time to visit Karatsu for sightseeing.
What to pack for Karatsu in April
From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In April, Karatsu sees daytime highs around 17°C and nights near 12°C. Worth packing: rain gear and sun protection. About 11 days see rain.
Sea temperature near Karatsu in April
The nearest coast averages about 16°C in April — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 22 km away) is warmest in August at about 27°C and coldest in February near 14°C.
It's comfortable for a long swim from Jun 8 to Nov 21 — about 5.5 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 14 | 14 | 16 | 18 | 21 | 24 | 27 | 25 | 23 | 21 | 18 |
| Comfort | Cool | Bracing | Bracing | Cool | Cool | Refreshing | Warm | Warm | Warm | Refreshing | Refreshing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 16 | Cool |
| May | 18 | Cool |
| Jun | 21 | Refreshing |
| Jul | 24 | Warm |
| Aug | 27 | Warm |
| Sep | 25 | Warm |
| Oct | 23 | Refreshing |
| Nov | 21 | Refreshing |
| Dec | 18 | Cool |
UV index in Karatsu in April
Clear-sky midday UV in April peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Karatsu peaks around July 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 3 | 4 | 6 | 8 | 8 | 7 | 9 | 9 | 9 | 6 | 4 | 3 |
| Level | Moderate | Moderate | High | Very high | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 4 | Moderate |
| Mar | 6 | High |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 7 | Very high |
| Jul | 9 | Very high |
| Aug | 9 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Air quality in Karatsu in April
Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.
Air quality in Karatsu is worst in April — around 24 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (July, 11 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) | 17 | 20 | 24 | 24 | 21 | 16 | 11 | 11 | 12 | 11 | 14 | 13 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 17 | Moderate |
| Feb | 20 | Moderate |
| Mar | 24 | Moderate |
| Apr | 24 | Moderate |
| May | 21 | Moderate |
| Jun | 16 | Moderate |
| Jul | 11 | Good |
| Aug | 11 | Good |
| Sep | 12 | Good |
| Oct | 11 | Good |
| Nov | 14 | Moderate |
| Dec | 13 | Moderate |
Where is Karatsu?
Karatsu sits at 33.4°N, 130.0°E, 7 m above sea level, in Japan. The nearest listed city is Imarichō-kō, 21 km away.
Topography around Karatsu
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Karatsu.
Within 3 km, the terrain around Karatsu has only modest variations in elevation — a maximum elevation change of 218 m around an average of 38 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 899 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,318 m.
The land around Karatsu is covered by trees (41%), artificial surfaces (28%) and water (24%) within 3 km, trees (59%) and water (29%) within 16 km, and water (58%) and trees (29%) within 80 km.
Japan travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 100 V · 50 / 60 Hz
- Prices
- ≈ 65% of US
- price level, 2025
- GDP per capita
- $35,951
- 2025
- Happiness
- 6.1 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.2
- per 100k, 2023
- Road deaths
- 3.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Very low
- EF EPI 446
- 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 Karatsu (33.4425°, 129.9697°, elevation 7 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).