Weather in Mexico City 🇲🇽
Monthly weather averages & travel planning
September
Avg Temp
21°C
Rain Days
22 days
Sun Hours
9 hrs
Humidity
78%
North America › 🇲🇽 Mexico › Mexico City
Updated: March 2026
Is September a Good Time to Visit Mexico City?
5/10
Fair
September is a fair time to visit Mexico City (5/10). With 9 daily sunshine hours and only 22 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 12th sunniest of the year in Mexico City. Culture-focused travellers and those who prefer lighter crowds will find September a practical choice, with prices running lower than peak April without sacrificing all the good weather. October offers a similar profile at lower hotel rates if dates are flexible. Watch out for prolonged rain stretches: with 22 wet days, a fully outdoor itinerary is risky. Build in museum days and covered market visits as contingency. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.
vs August:21°C avg high
The single most important thing to know about visiting Mexico City in September: rain is a genuine factor across 22 days of the month, meaning your plans need built-in indoor alternatives. Precipitation totals 179mm for the month, spread across roughly 22 days, and 9 sunshine hours per day give you a reliable window for outdoor plans.
21°C
70°F
Avg High
12°C
54°F
Avg Low
22 days
179 mm total
Rain Days
9h
per day avg
Sunshine
78%
Humid
Humidity
Temperature in Mexico City in September
The 9°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. At 78% humidity, the 21°C daytime high feels 2-4°C warmer in practice: quick-dry fabrics and shade-seeking between noon and 3pm are the sensible response. UV index averages 6 this month, classed as moderate. Sunscreen is a sensible precaution for extended outdoor time, particularly at midday. Winds are calm at an average 12 km/h, so wind-chill is not a factor in planning your clothing. In Fahrenheit: 70°F average high, 54°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Temperature Trends
High
Low
Rainfall (mm)
0-20 mm21-50 mm51-100 mm100+ mm
What to Wear in Mexico City in September
Morning12°CBefore the day warms up
Afternoon21°CPeak daytime temperature
Evening15°CAfter sunset cools down
Packing for Mexico City in September means dressing for 21°C days and 12°C evenings. A light cotton tee with a casual overshirt works well at 21°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 12°C, a modest 9°C drop that a light cardigan or denim jacket covers. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues. With 22 rain days expected, a compact travel umbrella is worth the bag space. A waterproof jacket is better than an umbrella if you plan full-day outdoor routes. At 78% average humidity, quick-dry synthetic or bamboo fabrics dry overnight and stay comfortable longer than cotton.
Local tip: Mexico City sees heavy rain periods where a compact travel umbrella can feel inadequate. A packable waterproof jacket offers better coverage for prolonged downpours and leaves both hands free for maps and cameras.
Events in Mexico City in September
September has no major festivals or public holidays in Mexico City, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
What to Pack for Mexico City in September
Based on 21°C average highs and 22 rainy days
- Light jacket or cardigan for cooler evenings
- Mix of short and long-sleeve layers
- Comfortable walking shoes with good arch support
- Compact folding umbrella
- Waterproof outer layer or packable rain jacket
- Quick-dry clothing that recovers fast after a shower
- Universal travel adapter
- Small day pack for city exploration
- Reusable water bottle
Best Activities in Mexico City in September
- Explore outdoor markets and street food stallsMid-morning (10am-12pm)At 21°C, the temperature is ideal for extended walking without overheating
- Guided walking tour of the historic centreMorning or late afternoonComfortable temperatures allow several hours on foot without fatigue
- Visit rooftop viewpoints and observation decksGolden hour (1 hour before sunset)Warm clear evenings provide exceptional visibility for panoramic photography
- Day trip to the surrounding countryside or coastFull day (depart by 8am)September is reliably dry enough for rural day trips without weather risk
- Spend a morning in the national or city art museumOpens at 10am; arrive earlyWith 22 rain days expected, having a full-day indoor plan is practical insurance
- Cooking class focused on regional cuisineHalf-day sessions run 10am-1pm or 3-6pmIndoor activity that fills a rainy half-day with genuine cultural content
- Visit covered historical sites: cathedral, palace, or bazaarAny time; most crowded middayRoofed monuments and covered markets provide exploration without weather exposure
- Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningSeptember brings distinct seasonal changes to public green spaces worth exploring
- Try the seasonal farmer's market for local produce and street foodSaturday morning markets typically 8am-1pmSeptember seasonal produce is at peak availability, offering dishes not found at other times of year
Why is Mexico City mild in September?
Mexico City's September climate is governed by the Inter-Tropical Convergence Zone (ITCZ), which draws moisture-laden trade winds across the region, producing the characteristic wet season rainfall of warm tropical cities. Daytime heat peaks around 21°C, moderated slightly by afternoon convective showers. Overnight temperatures remain warm at 12°C because the humid air retains heat effectively. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Frequently Asked Questions
Mexico City in September
In September, Mexico City experiences average highs of 21°C (70°F) and lows of 12°C (54°F). Expect around 22 rainy days and 9 hours of sunshine per day, with humidity averaging 78%. The 9°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 6, so sun protection is advisable on clear days.
Mexico City typically sees 22 rainy days in September, with total precipitation of around 179mm. This is a notably wet period. A waterproof jacket or compact umbrella is essential, and it is worth building indoor alternatives into your daily itinerary for the inevitable rainy stretches. For context, the driest month in Mexico City typically sees 4-6 fewer rain days than September.
Pack light layers, a light jacket for evenings, comfortable walking shoes, and sunscreen for Mexico City in September. Daytime temperatures of 21°C are pleasant, but the evening drop to 12°C means a jacket is essential if you plan to be out after dark. With 22 rainy days, bring a compact umbrella or waterproof jacket for unexpected showers. Comfortable walking shoes are a priority given the amount of ground most visitors cover.
September is a reasonable time to visit Mexico City. Expect 22 rainy days, so pack a light rain layer for flexibility. Average temperatures of 21°C make outdoor exploration comfortable during the dry periods. With 9 daily sunshine hours, there are reliable windows of good weather to plan outdoor activities around, even if the month is not the driest on the calendar.
The average high temperature in Mexico City in September is 21°C (70°F), and the average low is 12°C (54°F). The mean daily temperature is approximately 17°C (62°F). The day-to-night range of 9°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.
The best month to visit Mexico City is generally April. April offers the most sunshine at 12 hours per day and only 10 rainy days. Average temperatures reach 25°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around April gives you the best chance of dry, bright weather.
September is shoulder or low season in Mexico City, meaning fewer tourists and generally lower prices than peak months. With 9 sunshine hours and 22 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.
In September, Mexico City suits a range of activities thanks to mild temperatures around 21°C. With frequent rain, indoor activities and covered attractions are a smart choice. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 9 hours of sunshine, parks and waterfront walks are particularly enjoyable.
September ranks 12th sunniest of the year in Mexico City, with an average 9 daily sunshine hours. The driest months are December, January, and February. April is the hottest month (25°C avg high); January is the coolest (20°C). From here, temperatures fall 1°C into October. Compared to last month (August: 21°C high, 23 rain days), September is similarly warm and drier. September is one of the least sunny months, but that often means lower prices and fewer fellow tourists.
Year-Round Climate
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 20°C | 7°C | 4 | 10h | View |
| February | 22°C | 8°C | 4 | 11h | View |
| March | 24°C | 9°C | 6 | 11h | View |
| April | 25°C | 11°C | 10 | 12h | View |
| May | 25°C | 12°C | 13 | 12h | View |
| June | 23°C | 13°C | 19 | 10h | View |
| July | 21°C | 12°C | 24 | 10h | View |
| August | 21°C | 12°C | 23 | 10h | View |
| September | 21°C | 12°C | 22 | 9h | View |
| October | 20°C | 10°C | 14 | 10h | View |
| November | 20°C | 9°C | 7 | 10h | View |
| December | 20°C | 8°C | 3 | 10h | View |
January
4 rain days, 10h sun
20°7°
February
4 rain days, 11h sun
22°8°
March
6 rain days, 11h sun
24°9°
April
10 rain days, 12h sun
25°11°
May
13 rain days, 12h sun
25°12°
June
19 rain days, 10h sun
23°13°
July
24 rain days, 10h sun
21°12°
August
23 rain days, 10h sun
21°12°
September
22 rain days, 9h sun
21°12°
October
14 rain days, 10h sun
20°10°
November
7 rain days, 10h sun
20°9°
December
3 rain days, 10h sun
20°8°
Other Months in Mexico City
Plan Your Trip to Mexico City
Data Sources for Mexico City
Climate normals represent 30-year averages (1991-2020). Individual years may vary.