Ōmuta climate

Japan · 33.03°N, 130.45°E · elevation 15 m · population 131,974

Warmest month
August
high 32 °C89 °F
Coldest month
January
low 2 °C35 °F
Wettest month
July
394 mm16 in
Best time to visit
October and November
by our comfort score
Annual precipitation
2,130 mm84 in
January driest
Year average
17 °C62 °F
humid subtropical (Cfa)

Ōmuta (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 17 °C62 °F, and about 2,130 mm84 in of precipitation falls in an average year.

Temperature by month

Average highAverage low
0°5°10°15°20°25°30°35°40°60°80°JFMAMJJASOND32°89°2°35°January: high 10 °C / 49 °F, low 2 °C / 35 °FFebruary: high 12 °C / 53 °F, low 3 °C / 37 °FMarch: high 15 °C / 59 °F, low 5 °C / 42 °FApril: high 20 °C / 68 °F, low 10 °C / 50 °FMay: high 25 °C / 76 °F, low 15 °C / 58 °FJune: high 27 °C / 81 °F, low 19 °C / 67 °FJuly: high 30 °C / 87 °F, low 24 °C / 74 °FAugust: high 32 °C / 89 °F, low 24 °C / 75 °FSeptember: high 28 °C / 83 °F, low 20 °C / 69 °FOctober: high 23 °C / 74 °F, low 15 °C / 58 °FNovember: high 18 °C / 64 °F, low 9 °C / 48 °FDecember: high 12 °C / 53 °F, low 4 °C / 39 °F

Precipitation by month

Precipitation per month (mminches)
010020030040004812JJanuary: 69 mm / 2.7 inFFebruary: 101 mm / 4.0 inMMarch: 130 mm / 5.1 inAApril: 157 mm / 6.2 inMMay: 182 mm / 7.2 inJJune: 383 mm / 15.1 inJJuly: 394 mm / 15.5 inAAugust: 213 mm / 8.4 inSSeptember: 207 mm / 8.1 inOOctober: 117 mm / 4.6 inNNovember: 96 mm / 3.8 inDDecember: 82 mm / 3.2 in39415.5

Ōmuta climate table

Monthly averages, 2001–2025
MonthHigh °C°FLow °C°FMean °C°FPrecip. mmin
Jan1049235642692.7
Feb12533377451014.0
Mar155954210501305.1
Apr2068105015591576.2
May2576155820671827.2
Jun27811967237438315
Jul30872474278139416
Aug3289247528822138.4
Sep2883206924762078.1
Oct2374155819661174.6
Nov18649481356963.8
Dec1253439846823.2
Year328923517622,13084

“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.

Humidity, cloud, sun and daylight
MonthHumid.CloudSolarDaylight
Jan81%73%2.210:12
Feb79%71%2.910:58
Mar78%67%4.011:53
Apr78%66%4.812:58
May79%69%5.213:51
Jun84%81%4.514:19
Jul86%74%4.714:08
Aug83%65%5.113:22
Sep84%67%4.112:19
Oct82%59%3.611:18
Nov81%61%2.610:24
Dec81%69%2.09:59

Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.

What the climate of Ōmuta is like

The warmest month is August, with an average high of 32 °C89 °F and a low of 24 °C75 °F. The coldest is January, when highs average 10 °C49 °F and lows 2 °C35 °F. Seasons are strongly marked: the warmest month is on average 22.1 °C39.8 °F warmer than the coldest.

It is very wet, receiving about 2,130 mm84 in of precipitation per year. The wettest three-month stretch is June–August, which brings 46% of the annual total. The wettest month is July (394 mm16 in), the driest is January (69 mm2.7 in).

Relative humidity ranges from 78% in April to 86% in July. The clearest skies (lowest average cloud amount, 59%) are typical of October. Average wind speed near the ground ranges from 4 km/h (2 mph) in June to 6 km/h (3 mph) in January. Daylight lasts from about 10.0 hours in December to 14.3 hours in June.

Best time to visit Ōmuta

Based on these averages, the most comfortable months for sightseeing and outdoor activities are October and November: average highs of 18 °C64 °F to 23 °C74 °F with 96 mm3.8 in to 117 mm4.6 in of precipitation per month.

The most challenging month is July, which is hot, with average highs of 30 °C87 °F, very wet (394 mm16 in) and humid (86% relative humidity).

Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.

What to pack for Ōmuta

  • Winter (December–February) — highs 1049 to 12 °C53 °F, lows 235 to 4 °C39 °F, about 84 mm3.3 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
  • Spring (March–May) — highs 1559 to 25 °C76 °F, lows 542 to 15 °C58 °F, about 156 mm6.1 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
  • Summer (June–August) — highs 2781 to 32 °C89 °F, lows 1967 to 24 °C75 °F, about 330 mm13 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
  • Autumn (September–November) — highs 1864 to 28 °C83 °F, lows 948 to 20 °C69 °F, about 140 mm5.5 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.

How Ōmuta compares

Compared with Saga, about 26 km to the northwest, Ōmuta has practically the same average temperature and receives a similar amount of precipitation. The difference is largest in December (0.9 °C1.7 °F cooler).

Of the 111 places in Japan covered by World Climates, Ōmuta is the 26th warmest by annual mean temperature and the 8th wettest by annual precipitation. See all of them on the Japan climate page.

Places in other countries with the most similar temperature and rainfall pattern: Ningbo (China, Cfa), Cixi (China, Cfa) and Lianghu (China, Cfa).

Nearby places

  • Saga 26 km · 17 °C62 °F · 2,078 mm82 in
  • Kumamoto 34 km · 17 °C62 °F · 2,130 mm84 in
  • Isahaya 44 km · 16 °C61 °F · 2,078 mm82 in
  • Honmachi 60 km · 17 °C63 °F · 2,326 mm92 in
  • Nagasaki 62 km · 17 °C62 °F · 2,078 mm82 in
  • Fukuoka 63 km · 16 °C61 °F · 1,901 mm75 in
  • Karatsu 64 km · 17 °C63 °F · 1,963 mm77 in
  • Sasebo 69 km · 17 °C62 °F · 2,078 mm82 in

All places in Japan

Frequently asked questions

What is the warmest month in Ōmuta?

August is the warmest month in Ōmuta, with an average high of 32 °C (89 °F) and an average low of 24 °C (75 °F).

What is the coldest month in Ōmuta?

January is the coldest month, with an average high of 10 °C (49 °F) and an average low of 2 °C (35 °F).

When does it rain the most in Ōmuta?

July is the wettest month with about 394 mm (15.5 in) of precipitation; January is the driest with about 69 mm (2.7 in).

What is the best time to visit Ōmuta?

Judging by long-term averages, the most comfortable months are October and November.

About this data

All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.

The grid cell’s average elevation is 229 m, while Ōmuta lies at about 15 m. Temperatures on this page were therefore adjusted by +1.4 °C2.5 °F using the standard lapse rate of 6.5 °C per 1,000 m.

Sources and method