Climate averages 1991–2020

Ba Vì weather
in September.

A warm, very wet month: the 5th warmest and the 9th driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 27.9°C Daytime mean, September
Average low 22.2°C Night-time mean, September
Rainfall 236 mm 18 days with ≥1 mm
Daylight 12 h Sunrise to sunset, per day
Every month in Ba Vì · average highYear overview

September is a warm month in Ba Vì: daytime highs average 27.9°C and nights cool to about 22.2°C. By daytime temperature it is the 5th warmest of the 12 months.

Expect about 236 mm of rain on roughly 18 days, which makes September a very wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 17 min on an average September day.

The nearest other city in this atlas is Sơn Tây (14 km away). In September its highs average 30.0°C, 2.1°C warmer than Ba Vì, with 201 mm of rain.

Among the 136 cities listed in Vietnam, Ba Vì ranks joint 124th of 136 for the warmest September highs and joint 41st of 136 for the driest September (rainfall, lowest first). The mean September high of those 136 cities is 29.7°C; Ba Vì is 1.8°C cooler than that mean.

From September to October, average highs fall by 2.3°C to 25.6°C, and monthly rainfall falls from 236 mm to 133 mm.

The annual picture

September in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. 101520253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 3500

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Ba Vì climate table

1991–2020
Monthly climate averages for Ba Vì, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 17.3°C12.0°C12.0°C377.611.011 h
February 19.5°C13.5°C13.5°C246.611.411 h
March 22.9°C16.4°C16.4°C519.012.012 h
April 26.9°C19.8°C19.8°C10411.112.613 h
May 29.0°C22.2°C22.2°C24418.313.113 h
June 30.3°C23.8°C23.8°C23119.013.413 h
July 29.9°C23.8°C23.8°C27821.113.313 h
August 29.2°C23.3°C23.3°C33022.912.913 h
September, selected 27.9°C22.2°C22.2°C23618.412.312 h
October 25.6°C19.9°C19.9°C13312.011.712 h
November 22.5°C16.5°C16.5°C587.411.211 h
December 18.5°C12.8°C12.8°C326.310.911 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

September in nearby cities

Distance from Ba Vì

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Ba Vì) is explained once on the Ba Vì year overview and on the Sources, method and limits page.