Climate averages 1991–2020

Viacha weather
in September.

A mild, fairly dry month: the 3rd warmest and the 5th driest of the year.

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

Average high 15.2°C Daytime mean, September

Average low 0.7°C Night-time mean, September

Rainfall 32 mm 10 days with ≥1 mm

Daylight 12 h Sunrise to sunset, per day

September is a mild month in Viacha: daytime highs average 15.2°C and nights cool to about 0.7°C. By daytime temperature it is the 3rd warmest of the 12 months.

Expect about 32 mm of rain on roughly 10 days, which makes September a fairly dry month (the 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 59 min on an average September day.

The nearest other city in this atlas is La Paz (23 km away). In September its highs average 14.3°C, 0.9°C cooler than Viacha, with 36 mm of rain.

Among the 14 cities listed in Bolivia, Viacha ranks 13th of 14 for the warmest September highs and 6th of 14 for the driest September (rainfall, lowest first). The mean September high of those 14 cities is 22.6°C; Viacha is 7.4°C cooler than that mean.

From September to October, average highs rise by 0.5°C to 15.7°C, and monthly rainfall rises from 32 mm to 53 mm.

The annual picture

September in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

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

Every month, side by side

Viacha climate table

1991–2020

Monthly climate averages for Viacha, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	13.8°C4.5°C	4.5°C	143	24.8	13.013 h
February	13.8°C4.2°C	4.2°C	124	22.7	12.613 h
March	13.7°C3.7°C	3.7°C	96	22.4	12.212 h
April	13.8°C2.2°C	2.2°C	46	13.5	11.712 h
May	14.1°C0.2°C	0.2°C	14	4.7	11.311 h
June	13.7°C-1.2°C	-1.2°C	8.2	2.5	11.211 h
July	13.5°C-1.6°C	-1.6°C	10	3.0	11.211 h
August	14.5°C-0.7°C	-0.7°C	16	4.5	11.612 h
September, selected	15.2°C0.7°C	0.7°C	32	9.6	12.012 h
October	15.7°C2.4°C	2.4°C	53	13.2	12.512 h
November	16.1°C3.4°C	3.4°C	58	13.9	12.913 h
December	14.8°C4.2°C	4.2°C	110	20.8	13.113 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 Viacha

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 Viacha) is explained once on the Viacha year overview and on the Sources, method and limits page.