Mexico City Weather in September
Mexico · Subtropical Highlands climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Mexico City sees average temperatures ranging from a low of 12.7°C (54.9°F) to a high of 22.6°C (72.7°F), with a mean of 16.9°C (62.4°F). Compared to the annual average of 17.2°C (63.0°F), this month is 0.3°C cooler than the yearly norm. Precipitation averages 243.4mm, making it approximately 155.0mm wetter than the monthly average of 88.0mm. The city receives an average of 10.0 hours of sunshine per day during September, with relative humidity averaging 76.0%. Wind speeds reach an average maximum of 15.7 km/h. For travelers, this month offers a temperature experience in Mexico City, with wetter-than-average conditions compared to the rest of the year.
Mexico City's altitude (2,240m) is the packing variable everyone forgets. I packed for 25°C days and shivered through 12°C nights — the swing is real. Layering is non-negotiable; bring a fleece even in May. The dry season (November-April) is the sweet window: 22°C, low rain, low humidity. Skip May-June when heat plus dust plus ozone make breathing uncomfortable. July-September is rainy season — spectacular afternoon thunderstorms but plan indoor mornings. Sunscreen is essential at altitude even on cloudy days. And drink water constantly; the thin air dehydrates you faster than you'd expect.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 17.0°C (62.6°F) | 16.9°C (62.4°F) | 16.2°C (61.2°F) |
| Rainfall | 261.3mm | 243.4mm | 71.1mm |
| Sunshine | 10.5 hrs | 10.0 hrs | 9.9 hrs |
| Humidity | 76.5% | 76.0% | 69.7% |
| Wind | 15.0 km/h | 15.7 km/h | 18.2 km/h |
| Rainy Days | 30.4 | 26.6 | 19.4 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Mexico City in September, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Mexico City in September?
The average temperature in Mexico City during September ranges from 12.7°C (54.9°F) to 22.6°C (72.7°F), with a mean of 16.9°C (62.4°F).
How much does it rain in Mexico City in September?
Mexico City receives an average of 243.4mm of precipitation in September, spread across approximately 26.6 rainy days.
What should I pack for Mexico City in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella. Rain gear is essential — this month averages 243.4mm of precipitation.
Is September a good time to visit Mexico City?
September is a month with challenging conditions. Plan activities carefully and stay hydrated.
Other Months for Mexico City
Cities with Similar September Climate (Subtropical Highlands)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 19.43°, -99.13°. Timezone: America/Mexico_City. Last updated: 2026-07-30.