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Long Bien weather by month: averages, rainfall & climate trends

Average temperatures in Long Bien follow a clear seasonal rhythm, rising and falling by 12.8°C over the course of the year. Rainfall leans toward the stretch from May to October. Long Bien weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+5.3°Chigh well above average

34° / 25°Today
29° / 22°Average
see today in detail →

How it's changed

+1.3°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49166days above 30°C a year now (2016–2025) · 126 in the 1940sdays above 30°C · 126 in the 1940s+1.3°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 42 mmhigh 20°low 14°February, rain 41 mmhigh 21°low 15°March, rain 61 mmhigh 25°low 18°April, rain 102 mmhigh 29°low 22°May, rain 227 mmhigh 32°low 25°June, rain 257 mmhigh 33°low 27°July, rain 253 mmhigh 33°low 27°August, rain 359 mmhigh 32°low 26°September, rain 275 mmhigh 31°low 25°October, rain 161 mmhigh 29°low 22°November, rain 59 mmhigh 26°low 18°December, rain 29 mmhigh 22°low 15°wettest month August, 359 mm · 1,868 mm a yearsee month by month →

Right now

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

Right now

33.9°

38°feels like
46%humidity
21°dew point
4 km/hfrom SE
UV index1.5
sunrise05:53sunset17:28day length11h 35m
TodayPartly cloudy34°25°
WedMostly clear34°25°
ThuPartly cloudy33°26°
FriPartly cloudy33°25°
SatPartly cloudy34°25°
SunPartly cloudy34°26°
MonPartly cloudy33°26°

On this date: October 20

Today (forecast)
34° / 25°
Average for October 20
29° / 22°

High well above average · +5.3°C

  • Highest since 1940: 34.4° · 2002
  • Lowest since 1940: 15.5° · 1956
  • One year ago: 30° / 23°

Every October 20 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 20 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 Long Bien is sampled from the ECMWF ERA5 reanalysis at 21.03°N, 105.90°E, with daily records since 1940.

Coordinates
21.03°N, 105.90°E
Time zone
Asia/Bangkok
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

28 of the last 31 days were warmer than the historical average for that date. Average difference: +2.5°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

The year peaks in July, at around 33.3°C by mid-afternoon, with nights around 26.8°C. In a typical recent year, around 165 days reach 30°C or more. In January, the coolest month, afternoons reach about 20.2°C and nights dip to 13.7°C. Frost is essentially unknown.

The yearly total for Long Bien comes to about 1,868 mm; monthly amounts range from 29 mm in December up to 359 mm in August.

Over the full record (since 1940), the annual mean temperature in Long Bien has risen by 1.3°C between its first decade and its last. The year-by-year charts below trace that shift in detail.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 13°C. Wettest month: August (~359 mm). Whole year averages ~1,868 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.

Long Bien 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
January20.2°13.7°42 mm10.9 h34.4° (1969)2.9° (1955)
February21.4°15.2°41 mm11.3 h36.7° (1973)5.3° (1957)
March24.6°18.2°61 mm11.9 h37.3° (1987)6.9° (1986)
April28.5°21.9°102 mm12.5 h38.7° (2024)12.4° (1970)
May31.7°25.0°227 mm13.0 h39.6° (1969)17.0° (1994)
June33.1°26.6°257 mm13.3 h40.8° (1949)20.5° (1964)
July33.3°26.8°253 mm13.2 h40.9° (1946)22.3° (1972)
August32.2°26.0°359 mm12.7 h40.5° (1946)21.6° (1966)
September31.1°24.7°275 mm12.1 h36.8° (1956)16.5° (1970)
October28.7°21.9°161 mm11.5 h35.2° (2023)12.2° (1978)
November25.5°18.3°59 mm11.0 h34.2° (1997)7.6° (1956)
December21.9°14.6°29 mm10.7 h30.9° (2018)4.1° (1975)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.3°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

Sep–Nov is warming fastest: +0.23°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: 125.9 early in the record → 166.3 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 1946, coldest in 1955: 40.9°C / 2.9°C.

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

Annual rainfall

~1,868 mm/year on average. Last decade: +6% vs that average. Long-term trend: +20 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 Long Bien

Which is the warmest month in Long Bien?
On long-term average, the warmest month in Long Bien is July (mean daily temperature of about 29.6°C) and the coolest is January (about 16.8°C).
How does today's temperature in Long Bien compare to the historical average?
On October 20, 2026, Long Bien is forecast to reach a high of 33.9°C and a low of 25.0°C. The long-term average for this date (the full record since 1940) is a high of 28.6°C and a low of 21.7°C, so today's high is 5.3°C warmer than that average.
How much has Long Bien warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Long Bien is about 1.3°C warmer.
How much does it rain in Long Bien?
Long Bien receives about 1,868 mm of precipitation per year on long-term average, with August typically the wettest month.
What is the average temperature in Long Bien?
Over the full record (since 1940), the annual mean temperature in Long Bien is about 24.0°C. The warmest month is July and the coolest is January.
What are the average temperatures in Long Bien by month?
Average daily highs and lows for each month in Long Bien (°C, full record since 1940): January 20°/14°, February 21°/15°, March 25°/18°, April 29°/22°, May 32°/25°, June 33°/27°, July 33°/27°, August 32°/26°, September 31°/25°, October 29°/22°, November 26°/18°, December 22°/15°.
What is the weather like in Long Bien in summer?
Summer in Long Bien (June to August) is wet and hot. Expect 32–33°C by day and 26–27°C at night, with July the warmest month. About 290 mm of rain a month. No season is wetter.
What is the weather like in Long Bien in winter?
December to February is winter in Long Bien, and it is mild. Daytime highs sit at 20–22°C and nights at 14–15°C; January is the coldest month. Rain is steady at around 37 mm a month. It is the driest season of the year.
What is the weather like in Long Bien in spring?
March to May is spring in Long Bien, and it is wet and warm. March is still 25°C in the afternoon and 18°C at night, May already 32°C and 25°C. Rain rises from 61 mm in March to 227 mm in May.
What is the weather like in Long Bien in autumn?
In autumn, September through November, Long Bien is wet and warm. September is still 31°C by day and 25°C at night; by November it is down to 26°C and 18°C. Rain eases through the season, 275 mm in September to 59 mm in November.

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