Saga climate

Japan · 33.23°N, 130.30°E · elevation 4 m · population 233,301

Warmest month
August
high 31 °C88 °F
Coldest month
January
low 3 °C38 °F
Wettest month
July
352 mm14 in
Best time to visit
October
by our comfort score
Annual precipitation
2,078 mm82 in
January driest
Year average
17 °C62 °F
humid subtropical (Cfa)

Saga (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 17 °C62 °F, and about 2,078 mm82 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°JFMAMJJASOND31°88°3°38°January: high 10 °C / 50 °F, low 3 °C / 38 °FFebruary: high 11 °C / 53 °F, low 4 °C / 39 °FMarch: high 15 °C / 58 °F, low 6 °C / 43 °FApril: high 19 °C / 67 °F, low 10 °C / 51 °FMay: high 24 °C / 75 °F, low 15 °C / 59 °FJune: high 27 °C / 80 °F, low 19 °C / 67 °FJuly: high 30 °C / 86 °F, low 24 °C / 74 °FAugust: high 31 °C / 88 °F, low 24 °C / 76 °FSeptember: high 28 °C / 82 °F, low 21 °C / 70 °FOctober: high 23 °C / 73 °F, low 16 °C / 60 °FNovember: high 17 °C / 63 °F, low 11 °C / 51 °FDecember: high 12 °C / 53 °F, low 6 °C / 42 °F

Precipitation by month

Precipitation per month (mminches)
010020030040004812JJanuary: 71 mm / 2.8 inFFebruary: 99 mm / 3.9 inMMarch: 131 mm / 5.2 inAApril: 167 mm / 6.6 inMMay: 186 mm / 7.3 inJJune: 333 mm / 13.1 inJJuly: 352 mm / 13.9 inAAugust: 225 mm / 8.9 inSSeptember: 201 mm / 7.9 inOOctober: 117 mm / 4.6 inNNovember: 103 mm / 4.1 inDDecember: 92 mm / 3.6 in35213.9

Saga climate table

Monthly averages, 2001–2025
MonthHigh °C°FLow °C°FMean °C°FPrecip. mminFrost days
Jan1050338744712.83
Feb1153439846993.92
Mar155864310511315.20
Apr1967105115591676.60
May2475155919671867.30
Jun278019672373333130
Jul308624742780352140
Aug3188247628822258.90
Sep2882217024762017.90
Oct2373166019661174.60
Nov1763115114571034.10
Dec1253642948923.60
Year318833817622,078826

“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.

Humidity, cloud, sun and daylight
MonthHumid.CloudSolarDaylight
Jan79%73%2.210:11
Feb78%71%2.910:57
Mar77%67%4.011:53
Apr78%66%4.812:58
May80%69%5.213:52
Jun84%81%4.514:20
Jul86%74%4.714:09
Aug83%65%5.113:22
Sep84%67%4.112:20
Oct81%59%3.611:17
Nov80%61%2.610:23
Dec79%69%2.09:58

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 Saga is like

The warmest month is August, with an average high of 31 °C88 °F and a low of 24 °C76 °F. The coldest is January, when highs average 10 °C50 °F and lows 3 °C38 °F. Seasons are strongly marked: the warmest month is on average 21.1 °C38 °F warmer than the coldest.

It is very wet, receiving about 2,078 mm82 in of precipitation per year. The wettest three-month stretch is June–August, which brings 44% of the annual total. The wettest month is July (352 mm14 in), the driest is January (71 mm2.8 in).

Relative humidity ranges from 77% in March 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 7 km/h (4 mph) in January. Daylight lasts from about 10.0 hours in December to 14.3 hours in June.

Best time to visit Saga

Based on these averages, the most comfortable months for sightseeing and outdoor activities are October: average highs of 23 °C73 °F to 23 °C73 °F with 117 mm4.6 in to 117 mm4.6 in of precipitation per month.

The most challenging month is July, which is very wet (352 mm14 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 Saga

  • Winter (December–February) — highs 1050 to 12 °C53 °F, lows 338 to 6 °C42 °F, about 87 mm3.4 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
  • Spring (March–May) — highs 1558 to 24 °C75 °F, lows 643 to 15 °C59 °F, about 162 mm6.4 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 2780 to 31 °C88 °F, lows 1967 to 24 °C76 °F, about 303 mm12 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 1763 to 28 °C82 °F, lows 1151 to 21 °C70 °F, about 141 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 Saga compares

Compared with Fukuoka, about 42 km to the north, Saga is on average 0.8 °C1.4 °F warmer and receives 9% more precipitation (2,078 mm82 in vs 1,901 mm75 in). The difference is largest in January (1.6 °C2.9 °F warmer).

Of the 111 places in Japan covered by World Climates, Saga is the 17th warmest by annual mean temperature and the 15th 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 Jeju City (South Korea, Cfa).

Nearby places

  • Ōmuta 26 km · 17 °C62 °F · 2,130 mm84 in
  • Karatsu 39 km · 17 °C63 °F · 1,963 mm77 in
  • Fukuoka 42 km · 16 °C61 °F · 1,901 mm75 in
  • Isahaya 50 km · 16 °C61 °F · 2,078 mm82 in
  • Sasebo 54 km · 17 °C62 °F · 2,078 mm82 in
  • Kumamoto 60 km · 17 °C62 °F · 2,130 mm84 in
  • Nagasaki 66 km · 17 °C62 °F · 2,078 mm82 in
  • Kitakyushu 86 km · 17 °C62 °F · 1,860 mm73 in

All places in Japan

Frequently asked questions

What is the warmest month in Saga?

August is the warmest month in Saga, with an average high of 31 °C (88 °F) and an average low of 24 °C (76 °F).

What is the coldest month in Saga?

January is the coldest month, with an average high of 10 °C (50 °F) and an average low of 3 °C (38 °F).

When does it rain the most in Saga?

July is the wettest month with about 352 mm (13.9 in) of precipitation; January is the driest with about 71 mm (2.8 in).

What is the best time to visit Saga?

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

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 116 m, while Saga lies at about 4 m. Temperatures on this page were therefore adjusted by +0.7 °C1.3 °F using the standard lapse rate of 6.5 °C per 1,000 m.

Sources and method