Climate averages 1991–2020
Retalhuleu weather
in September.
A hot, very wet month: the 11th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Retalhuleu: daytime highs average 28.1°C and nights cool to about 21.9°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 456 mm of rain on roughly 29 days, which makes September a very wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 13 min on an average September day.
The nearest other city in this atlas is Mazatenango (19 km away). In September its highs average 27.1°C, 1.0°C cooler than Retalhuleu, with 542 mm of rain.
Among the 23 cities listed in Guatemala, Retalhuleu ranks 4th of 23 for the warmest September highs and 19th of 23 for the driest September (rainfall, lowest first). The mean September high of those 23 cities is 24.7°C; Retalhuleu is 3.4°C warmer than that mean.
From September to October, average highs fall by 0.4°C to 27.7°C, and monthly rainfall falls from 456 mm to 384 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Retalhuleu climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.0°C20.3°C | 20.3°C | 18 | 4.9 | 11.411 h |
| February | 31.1°C20.7°C | 20.7°C | 15 | 3.8 | 11.712 h |
| March | 31.6°C21.6°C | 21.6°C | 36 | 8.4 | 12.012 h |
| April | 31.5°C22.4°C | 22.4°C | 93 | 14.4 | 12.512 h |
| May | 29.8°C22.5°C | 22.5°C | 351 | 27.0 | 12.813 h |
| June | 28.5°C22.2°C | 22.2°C | 374 | 28.4 | 13.013 h |
| July | 28.9°C22.2°C | 22.2°C | 287 | 27.0 | 12.913 h |
| August | 28.8°C22.2°C | 22.2°C | 361 | 28.5 | 12.613 h |
| September, selected | 28.1°C21.9°C | 21.9°C | 456 | 29.2 | 12.212 h |
| October | 27.7°C21.7°C | 21.7°C | 384 | 27.7 | 11.812 h |
| November | 28.3°C21.4°C | 21.4°C | 116 | 15.5 | 11.511 h |
| December | 29.2°C20.5°C | 20.5°C | 27 | 6.0 | 11.311 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
- Mazatenango in SeptemberGuatemala · 19 kmHigh 27.1°C · Low 20.5°C · 542 mm rain
- Coatepeque in SeptemberGuatemala · 27 kmHigh 26.0°C · Low 19.5°C · 629 mm rain
- Quetzaltenango in SeptemberGuatemala · 38 kmHigh 19.1°C · Low 13.8°C · 479 mm rain
- Totonicapán in SeptemberGuatemala · 54 kmHigh 19.1°C · Low 12.8°C · 264 mm rain
- Malacatán in SeptemberGuatemala · 58 kmHigh 26.4°C · Low 18.4°C · 462 mm rain
- Santa Lucía Cotzumalguapa in SeptemberGuatemala · 74 kmHigh 26.6°C · Low 19.5°C · 374 mm rain
- Tapachula in SeptemberMexico · 75 kmHigh 28.0°C · Low 20.9°C · 697 mm rain
- Chichicastenango in SeptemberGuatemala · 76 kmHigh 20.8°C · Low 14.0°C · 265 mm rain
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 limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Retalhuleu) is explained once on the Retalhuleu year overview and on the Sources, method and limits page.