WeatherJourney.com

Saga weather by month: averages, rainfall & climate trends

Seasons run to extremes in Saga: monthly means span 21.6°C between the coldest month and the warmest. The heavier rain months run from May to September. Saga weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.3°Chigh above average

25° / 17°Today
22° / 14°Average
see today in detail →

How it's changed

+2.4°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–494frost days a year now (2016–2025) · 13 in the 1940sfrost days a year · 13 in the 1940s70days above 30°C a year now (2016–2025) · 35 in the 1940sdays above 30°C · 35 in the 1940s+2.4°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 65 mmhigh 10°low 3°February, rain 84 mmhigh 11°low 4°March, rain 116 mmhigh 14°low 6°April, rain 154 mmhigh 20°low 11°May, rain 178 mmhigh 24°low 16°June, rain 333 mmhigh 27°low 20°July, rain 296 mmhigh 30°low 24°August, rain 188 mmhigh 32°low 25°September, rain 195 mmhigh 28°low 21°October, rain 103 mmhigh 23°low 15°November, rain 84 mmhigh 18°low 10°December, rain 65 mmhigh 12°low 5°wettest month June, 333 mm · 1,860 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

20.4°

22°feels like
75%humidity
16°dew point
2 km/hfrom W
UV index0.0
sunrise06:27sunset17:39day length11h 11m
TodayOvercast25°17°
ThuPartly cloudy21°14°
FriOvercast23°14°
SatShowers25°20°
SunRain24°22°
MonShowers25°21°
TueOvercast24°15°

On this date: October 21

Today (forecast)
25° / 17°
Average for October 21
22° / 14°

High above average · +2.3°C

  • Highest since 1940: 27.5° · 2024
  • Lowest since 1940: 8.3° · 1978
  • One year ago: 22° / 18°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 21 on record (n = 86). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Saga is sampled from the ECMWF ERA5 reanalysis at 33.23°N, 130.30°E, with daily records since 1940.

Coordinates
33.23°N, 130.30°E
Time zone
Asia/Tokyo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

24 of the last 30 days were warmer than the historical average for that date. Average difference: +1.7°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

August brings the year's peak warmth, with afternoons typically reaching 31.5°C and nights around 24.9°C. On about 120 nights a year, the temperature never drops below 20°C. In January, the coolest month, afternoons reach about 9.5°C and nights dip to 3.2°C.

In total, Saga averages about 1,860 mm of precipitation a year; June is usually the wettest month (333 mm) and December the driest (65 mm).

Comparing the record's first decade with its most recent one, Saga now averages 2.4°C warmer than it did in the 1940s. The count of days past 30°C has risen from roughly 35 a year to 70 between the record's first and last decades.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 22°C. Wettest month: June (~333 mm). Whole year averages ~1,860 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 116 rainy days a year: most in July (~16), fewest in November (~6).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Saga month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January9.5°3.2°65 mm610.0 h19.7° (1969)−3.3° (1963)
February10.6°3.6°84 mm710.8 h23.2° (2004)−5.8° (1968)
March14.3°6.5°116 mm911.8 h24.3° (1964)−3.0° (1981)
April19.6°11.3°154 mm1012.8 h29.1° (2021)0.6° (1972)
May23.8°15.7°178 mm1013.7 h34.0° (2000)6.9° (1958)
June26.5°20.1°333 mm1414.2 h35.2° (2004)12.0° (1959)
July30.2°24.4°296 mm1614.0 h37.4° (1994)14.4° (1966)
August31.5°24.9°188 mm1313.2 h37.4° (2024)17.6° (1950)
September28.0°21.2°195 mm1212.2 h37.7° (2010)10.3° (1973)
October22.9°15.2°103 mm611.2 h31.8° (2005)4.2° (1986)
November17.5°10.0°84 mm610.2 h26.6° (2023)0.0° (1963)
December12.0°5.2°65 mm69.8 h23.3° (2018)−2.5° (1980)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.4°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.29°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Sep–Nov is warming fastest: +0.31°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 34.8 early in the record → 69.8 recently. Frost days: 13 → 4.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2010, coldest in 1968: 37.7°C / −5.8°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,860 mm/year on average. Last decade: +6% vs that average. Long-term trend: +43 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Saga

Which is the warmest month in Saga?
On long-term average, the warmest month in Saga is August (mean daily temperature of about 27.8°C) and the coolest is January (about 6.2°C).
How does today's temperature in Saga compare to the historical average?
On October 21, 2026, Saga is forecast to reach a high of 24.5°C and a low of 17.1°C. The long-term average for this date (the full record since 1940) is a high of 22.2°C and a low of 14.2°C, so today's high is 2.3°C warmer than that average.
How much has Saga warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Saga is about 2.4°C warmer.
How much does it rain in Saga?
Saga receives about 1,860 mm of precipitation per year on long-term average, with June typically the wettest month.
What is the average temperature in Saga?
Over the full record (since 1940), the annual mean temperature in Saga is about 16.8°C. The warmest month is August and the coolest is January.
What are the average temperatures in Saga by month?
Average daily highs and lows for each month in Saga (°C, full record since 1940): January 10°/3°, February 11°/4°, March 14°/6°, April 20°/11°, May 24°/16°, June 27°/20°, July 30°/24°, August 32°/25°, September 28°/21°, October 23°/15°, November 18°/10°, December 12°/5°.
What is the weather like in Saga in summer?
In summer, June through August, Saga is wet and warm. June starts at 27°C by day and 20°C at night; by August it is 32°C and 25°C. Rain falls off from 333 mm on 14 days in June to 188 mm on 13 days in August. No season is wetter.
What is the weather like in Saga in winter?
December to February is winter in Saga, and it is on the cool side. Daytime highs sit at 10–12°C and nights at 3–5°C; January is the coldest month. Rain is steady at around 71 mm a month, spread over roughly 7 days. It is the driest season of the year.
What is the weather like in Saga in spring?
March to May is spring in Saga, and it is wet and mild. March starts at 14°C by day and 6°C at night; by May it is 24°C and 16°C. Rain rises from 116 mm on 9 days in March to 178 mm on 10 days in May.
What is the weather like in Saga in autumn?
September to November is autumn in Saga, and it is wet and pleasantly warm. It cools from 28°C by day and 21°C at night in September to 18°C and 10°C in November. Rain eases through the season: 12 rainy days and 195 mm in September, 6 days and 84 mm in November.
How many days a year does it rain in Saga?
On long-term average, Saga has about 116 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,860 mm.

Weather in nearby cities