Climate averages 1991–2020

Chetumal weather
in September.

A hot, very wet month: the 5th warmest and the 10th driest of the year.

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

Average high 30.6°C Daytime mean, September

Average low 24.6°C Night-time mean, September

Rainfall 186 mm 25 days with ≥1 mm

Daylight 12 h Sunrise to sunset, per day

September is a hot month in Chetumal: daytime highs average 30.6°C and nights cool to about 24.6°C. By daytime temperature it is the 5th warmest of the 12 months.

Expect about 186 mm of rain on roughly 25 days, which makes September a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 15 min on an average September day.

The nearest other city in this atlas is Belmopan (149 km away). In September its highs average 30.5°C, about as warm as Chetumal, with 150 mm of rain.

Among the 153 cities listed in Mexico, Chetumal ranks joint 26th of 153 for the warmest September highs and joint 106th of 153 for the driest September (rainfall, lowest first). The mean September high of those 153 cities is 26.5°C; Chetumal is 4.0°C warmer than that mean.

From September to October, average highs fall by 1.4°C to 29.2°C, and monthly rainfall rises from 186 mm to 190 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

Chetumal climate table

1991–2020

Monthly climate averages for Chetumal, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	26.9°C20.8°C	20.8°C	52	12.3	11.111 h
February	28.2°C21.6°C	21.6°C	24	7.2	11.512 h
March	29.7°C22.4°C	22.4°C	26	6.8	12.012 h
April	31.3°C24.0°C	24.0°C	32	7.4	12.613 h
May	31.6°C24.8°C	24.8°C	93	15.3	13.013 h
June	30.4°C25.0°C	25.0°C	193	21.5	13.213 h
July	30.8°C24.9°C	24.9°C	120	20.9	13.113 h
August	31.1°C24.9°C	24.9°C	158	23.2	12.813 h
September, selected	30.6°C24.6°C	24.6°C	186	25.2	12.312 h
October	29.2°C23.5°C	23.5°C	190	21.8	11.712 h
November	27.8°C22.0°C	22.0°C	96	14.8	11.311 h
December	27.1°C21.2°C	21.2°C	55	13.3	11.011 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 Chetumal

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