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Jombang weather by month: averages, rainfall & climate trends

Jombang is warm in every month of the year; the seasonal dip amounts to just 1.9°C. Rainfall leans toward the stretch from November to April. Jombang weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.9°Chigh above average

37° / 24°Today
34° / 24°Average
see today in detail →

How it's changed

+1.1°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49345days above 30°C a year now (2016–2025) · 279 in the 1940sdays above 30°C · 279 in the 1940s+1.1°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 283 mmhigh 31°low 23°February, rain 262 mmhigh 31°low 23°March, rain 255 mmhigh 31°low 23°April, rain 171 mmhigh 31°low 23°May, rain 104 mmhigh 31°low 23°June, rain 60 mmhigh 31°low 22°July, rain 34 mmhigh 32°low 21°August, rain 24 mmhigh 32°low 22°September, rain 31 mmhigh 33°low 22°October, rain 85 mmhigh 34°low 23°November, rain 174 mmhigh 33°low 24°December, rain 251 mmhigh 32°low 24°wettest month January, 283 mm · 1,734 mm a yearsee month by month →

Right now

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

Right now

26.0°

30°feels like
83%humidity
23°dew point
9 km/hfrom SW
UV index0.3
sunrise05:04sunset17:25day length12h 20m
MonOvercast37°24°
TueOvercast33°25°
WedPartly cloudy34°25°
ThuMostly clear37°24°
FriPartly cloudy37°25°
SatPartly cloudy37°25°
SunOvercast37°25°

On this date: October 25

Today (forecast)
37° / 24°
Average for October 25
34° / 24°

High above average · +2.9°C

  • Highest since 1940: 37.6° · 1961
  • Lowest since 1940: 21.1° · 1968
  • One year ago: 32° / 24°

Every October 25 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 25 on record (n = 87). 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 Jombang is sampled from the ECMWF ERA5 reanalysis at 7.55°S, 112.23°E, with daily records since 1940.

Coordinates
7.55°S, 112.23°E
Time zone
Asia/Jakarta
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

31 of the last 31 days were warmer than the historical average for that date. Average difference: +1.1°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

October brings the year's peak warmth, with afternoons typically reaching 33.9°C and nights around 23.3°C. In July, the coolest month, afternoons reach about 31.6°C and nights dip to 21.5°C.

In total, Jombang averages about 1,734 mm of precipitation a year; January is usually the wettest month (283 mm) and August the driest (24 mm).

Comparing the record's first decade with its most recent one, Jombang now averages 1.1°C warmer than it did in the 1940s. The last decade has also run wetter, about 16% above the long-term precipitation average.

Climate graph (climograph)

October is the warmest month, July the coolest: a yearly swing of 2°C. Wettest month: January (~283 mm). Whole year averages ~1,734 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).

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.

Jombang 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 lowRainDaylightHighestLowest
January30.7°23.4°283 mm12.4 h35.5° (1943)20.3° (1949)
February30.6°23.3°262 mm12.2 h35.2° (1943)20.7° (1942)
March30.9°23.3°255 mm12.0 h35.1° (1948)18.8° (1943)
April31.3°23.2°171 mm11.8 h35.0° (1948)18.8° (1972)
May31.3°23.0°104 mm11.7 h34.5° (1963)16.5° (1946)
June31.4°22.1°60 mm11.6 h36.4° (1953)17.3° (1966)
July31.6°21.5°34 mm11.6 h34.8° (1962)16.5° (1942)
August32.4°21.6°24 mm11.8 h36.2° (1961)17.1° (1953)
September33.4°22.3°31 mm12.0 h37.6° (1953)17.9° (1961)
October33.9°23.3°85 mm12.2 h38.3° (1965)18.0° (1997)
November33.0°23.8°174 mm12.4 h38.6° (2019)20.5° (1968)
December31.5°23.6°251 mm12.4 h38.1° (2019)19.6° (1966)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.1°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: +0.13°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

Mar–May is warming fastest: +0.22°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: 278.5 early in the record → 344.7 recently. Frost days: 0 → 0.

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 2019, coldest in 1942: 38.6°C / 16.5°C.

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

Annual rainfall

~1,734 mm/year on average. Last decade: +16% vs that average. Long-term trend: +84 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 Jombang

Which is the warmest month in Jombang?
On long-term average, the warmest month in Jombang is October (mean daily temperature of about 27.9°C) and the coolest is July (about 25.9°C).
How does today's temperature in Jombang compare to the historical average?
On October 25, 2026, Jombang is forecast to reach a high of 36.6°C and a low of 24.2°C. The long-term average for this date (the full record since 1940) is a high of 33.7°C and a low of 23.5°C, so today's high is 2.9°C warmer than that average.
How much has Jombang warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Jombang is about 1.1°C warmer.
How much does it rain in Jombang?
Jombang receives about 1,734 mm of precipitation per year on long-term average, with January typically the wettest month.
What is the average temperature in Jombang?
Over the full record (since 1940), the annual mean temperature in Jombang is about 26.7°C. The warmest month is October and the coolest is July.
What are the average temperatures in Jombang by month?
Average daily highs and lows for each month in Jombang (°C, full record since 1940): January 31°/23°, February 31°/23°, March 31°/23°, April 31°/23°, May 31°/23°, June 31°/22°, July 32°/21°, August 32°/22°, September 33°/22°, October 34°/23°, November 33°/24°, December 32°/24°.

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