Climate Insights for Ashiya Ab

Onga-gun, Fukuoka Prefecture, Japan

Hottest
August
33°C peak
Coldest
January
4°C low
Wettest
July
257mm rain
Best to Visit
October
Mild temps & low rain

Climate Overview

The climate in Ashiya Ab is temperate. The average annual temperature is 18°C and approximately 1654mm of precipitation falls per year. Ashiya Ab receives a notable amount of rainfall throughout the year, including during its driest month. Ashiya Ab is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are January, February, December, when temperatures can drop to 4°C.

Temperature

10° 20° 30° 40° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Max: 10° Average: 7° Min: 4° Feb Max: 11° Average: 8° Min: 5° Mar Max: 15° Average: 12° Min: 8° Apr Max: 20° Average: 16° Min: 13° May Max: 24° Average: 20° Min: 17° Jun Max: 27° Average: 24° Min: 21° Jul Max: 31° Average: 28° Min: 25° Aug Max: 33° Average: 29° Min: 26° Sep Max: 29° Average: 25° Min: 23° Oct Max: 24° Average: 20° Min: 17° Nov Max: 18° Average: 14° Min: 11° Dec Max: 12° Average: 9° Min: 6°
Max
Average
Min

Temperatures in Ashiya Ab vary considerably across the year, with a 29°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 33°C and the mean temperature sits around 29°C. January is the coolest month, with minimum temperatures around 4°C and an average of 7°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between November and December, with a 6°C shift in average temperatures.

Precipitation

0mm 50mm 100mm 150mm 200mm 250mm 300mm Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Precipitation: 72mm Snow: 2mm Feb Precipitation: 75mm Snow: 1mm Mar Precipitation: 106mm Snow: 0mm Apr Precipitation: 139mm Snow: 0mm May Precipitation: 132mm Snow: 0mm Jun Precipitation: 224mm Snow: 0mm Jul Precipitation: 257mm Snow: 0mm Aug Precipitation: 223mm Snow: 0mm Sep Precipitation: 199mm Snow: 0mm Oct Precipitation: 82mm Snow: 0mm Nov Precipitation: 82mm Snow: 0mm Dec Precipitation: 63mm Snow: 1mm
Precipitation
Snow

Ashiya Ab is a fairly wet location, receiving approximately 1654mm of precipitation annually, which averages out to around 138mm per month. The wettest month is July, averaging 257mm of rainfall. June and August also tend to see above-average precipitation. The driest month is December, with just 63mm. That's 194mm less than July, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.

Wind

0km/h 5km/h 10km/h 15km/h 20km/h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Wind Speed: 19km/h Feb Wind Speed: 19km/h Mar Wind Speed: 18km/h Apr Wind Speed: 18km/h May Wind Speed: 16km/h Jun Wind Speed: 15km/h Jul Wind Speed: 16km/h Aug Wind Speed: 16km/h Sep Wind Speed: 17km/h Oct Wind Speed: 17km/h Nov Wind Speed: 16km/h Dec Wind Speed: 18km/h
Wind Speed

Ashiya Ab is mildly breezy, with an average annual wind speed of 17km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in June, with average winds dropping to 15km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 19km/h in winter, 17km/h in spring, 16km/h in summer, 17km/h in autumn.

Seasons

Winter
Dec 21
Spring
Mar 20
Summer
Jun 21
Autumn
Sep 23

89 days until Summer

It is currently spring in Ashiya Ab, which began on March 20, 2026. Ashiya Ab is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 33°C, while the coldest stretch bottoms out in January near 4°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

Spring

Temperatures range from 8 to 24°C. Rainfall is heavy, totalling around 377mm across the season with a monthly average of 126mm. Winds are moderate at around 17km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.

Summer

Temperatures range from 21 to 33°C. Rainfall is heavy, totalling around 703mm across the season with a monthly average of 234mm. Winds are moderate at around 16km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.

Autumn

Temperatures range from 11 to 29°C. Rainfall is heavy, totalling around 364mm across the season with a monthly average of 121mm. Winds are moderate at around 17km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.

Winter

Temperatures range from 4 to 12°C. Precipitation is moderate at around 210mm for the season, averaging 70mm per month. Winds are moderate at around 19km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.

Best Time to Visit

Jan
Feb
Mar 12°
Apr 16°
May 20°
Jun 24°
Jul 28°
Aug 29°
Sep 25°
Oct 20°
Nov 14°
Dec

The best time to visit Ashiya Ab is during October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 82mm per month. By contrast, August can be uncomfortably hot with highs reaching 33°C, while January is the coldest period with lows dropping to 4°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

Monthly Climate Data

The table below shows monthly climate averages for Ashiya Ab based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.

Month
Min Temperature
Max Temperature
Wind Speed
Precipitation
Snow
Jan
4 °C
10 °C
19 km/h
72 mm
2 cm
Feb
5 °C
11 °C
19 km/h
75 mm
1 cm
Mar Current
8 °C
15 °C
18 km/h
106 mm
0 cm
Apr
13 °C
20 °C
18 km/h
139 mm
0 cm
May
17 °C
24 °C
16 km/h
132 mm
0 cm
Jun
21 °C
27 °C
15 km/h
224 mm
0 cm
Jul
25 °C
31 °C
16 km/h
257 mm
0 cm
Aug
26 °C
33 °C
16 km/h
223 mm
0 cm
Sep
23 °C
29 °C
17 km/h
199 mm
0 cm
Oct
17 °C
24 °C
17 km/h
82 mm
0 cm
Nov
11 °C
18 °C
16 km/h
82 mm
0 cm
Dec
6 °C
12 °C
18 km/h
63 mm
1 cm
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Metric (°C, km/h)