Planning a trip to Cabo San Lucas in September puts you right in the middle of the destination's most dramatic season. The desert heats up, the Sea of Cortez reaches its warmest temperatures of the year, and marine life thrives in ways that other months simply can't match. It's a month of trade-offs, and the right information makes all the difference.
This guide breaks down exactly what to expect from Cabo's weather in September. We'll cover temperatures, rain patterns, ocean conditions, wildlife opportunities, packing essentials, and how all of it affects your plans. By the end, you'll know whether September fits what you're looking for and how to make the most of every day on the ground. Let's start with what the thermometer says.
What's the Average Temperature in Cabo San Lucas During September?
September sits firmly inside Cabo's hot season, and the numbers reflect it. Daytime highs consistently reach 90–94°F (32–34°C), while nighttime lows hover around 73–75°F (23–25°C). What stands out is how little variation there is within the month, since the difference between the warmest and coolest days is only about 4°F, so it doesn't matter which week you visit. Expect steady, reliable heat from start to finish.
How Hot Does It Get in Cabo San Lucas in September?
The raw temperature tells part of the story, but humidity tells the rest. September is Cabo's most humid month, pushing the heat index to around 93°F (34°C) even when the air temperature reads 91°F. That sticky, heavy feeling peaks noon to 3 PM, when shade and water feel essential.
An ocean breeze from the Pacific or the Sea of Cortez helps take the edge off, but scheduling anything physically demanding for early morning makes a real difference.
Is It Cold in Cabo San Lucas in September?
Cold isn't part of the equation in September, not even close. This is one of the warmest months of the year in Cabo, and temperatures rarely dip below the mid-70s even in the coolest hours before dawn. You won't need a single warm layer for outdoor activities.
What's the Temperature Like at Night in Cabo San Lucas in September?
Evenings don't bring much relief from the daytime warmth. Nighttime temperatures settle around 73–75°F (23–25°C), which means light summer clothing works perfectly for dinners, waterfront strolls, and late evening plans.
There's no need to pack layers or plan around cooling temperatures; the air stays warm and comfortable well past sunset, making open-air dining and beachside evenings easy to enjoy without a second thought.
Is the Water Warm Enough to Swim in September?
September delivers the warmest ocean water temperatures Cabo sees all year, averaging 84–85°F (29–29.5°C) with a range that can reach into the upper 80s. That kind of warmth makes swimming, snorkeling, and casual diving effortless: no wetsuit required.
A rash guard for sun protection is the only thing worth wearing in the water. For extended or repeated scuba dives, a thin 3mm wetsuit helps offset cumulative heat loss, but single dives feel perfectly comfortable without one. Visibility ranges from 40 to 90 feet, meaning the underwater world is as clear as it is warm.
Does It Rain in Cabo San Lucas in September?
Yes, September is the wettest month on Cabo's calendar, but "wettest" in an arid desert region doesn't mean what you might expect. The month averages just a few rainy days out of 30, which leaves 25 or more days completely dry. When rain does arrive, it tends to come in short, concentrated bursts rather than all-day downpours, so it rarely washes out an entire day of plans.
How Much Rain Should You Expect in Cabo San Lucas in September?
Total rainfall for the month lands between 80 and 116 mm (roughly 3 to 4.5 inches), which accounts for nearly a third of Cabo's entire annual precipitation. The rain that does fall tends to arrive in quick, intense showers that clear out relatively fast, leaving behind cooler air and often spectacular post-storm skies.
Is September Part of the Rainy Season in Cabo San Lucas?
September marks the peak of Cabo's rainy season, which runs from roughly July through October. It's the single wettest month within that window: August averages about 92 mm, September jumps to 116 mm, and October drops sharply to 33 mm. So while you're visiting during the height of the wet season, the descent toward drier conditions is just weeks away, and most days still deliver the sunshine Cabo is known for.
Should You Worry About Storms in Cabo San Lucas in September?
September is statistically the most active month for tropical weather in the Eastern Pacific, and the Baja Peninsula isn't immune. That said, direct impacts remain uncommon; on average, under one day in September is affected by a passing tropical storm.
The region upgraded emergency infrastructure significantly after Hurricane Odile in 2014. Travel insurance that covers weather-related disruptions is essential, and monitoring the National Hurricane Center's Eastern Pacific forecasts gives you plenty of lead time if a system develops.
Is It Windy in Cabo San Lucas in September?
Wind conditions in September are among the calmest of the year, averaging just 8.3 mph with almost no variation throughout the month. That steady, light breeze creates ideal conditions for beach days: no fighting with umbrellas or getting sandblasted on shore. It also means calmer surface waters for snorkeling, paddleboarding, and kayaking.
The gentle airflow off the Pacific provides welcome cooling during peak heat hours without disrupting any water-based plans.
What Wildlife Shows Up in Cabo San Lucas in September?
September is one of the most rewarding months for marine life in Cabo. Sea turtles arrive in numbers as nesting season hits its stride, and California sea lion colonies return with newborn pups that swim playfully around snorkelers and divers.
Hammerhead sharks patrol deeper sites like Gordo Banks, while manta rays, mobula rays, and massive schools of jacks and snapper fill the warm, clear water. Humpback whales and whale sharks are notably absent; whales don't arrive until November, and whale shark tours don't begin until October, but the sheer variety of everything else makes September's underwater world exceptional.
Does the Weather Affect Tours in Cabo San Lucas During September?
Most tours continue to operate in September, though the heat and occasional rain bring adjustments. Land-based adventures like ATV excursions often shift to early morning departures to avoid peak temperatures. Water activities benefit from the warm, calm conditions, running comfortably through midday.
The main disruption risk comes from tropical weather systems, which can shut down ocean-based tours for a day or more. If weather forces a cancellation, you'll typically receive a full refund or the option to reschedule. Building flexibility into your itinerary helps you adapt without losing out.
What to Bring for Cabo San Lucas in September
Weather determines everything you pack. September's conditions in Cabo mean you'll want specific gear to stay comfortable and make the most of your trip. Breathable, quick-dry fabrics are essential; pack three to four swimsuits since humidity prevents overnight drying.
A light rain jacket earns its place in your bag for sudden showers, and waterproof sandals handle both beach days and wet streets. Sun-protective clothing like long-sleeve lightweight shirts and wide-brimmed hats matters more than you'd expect, even on partly cloudy days.
Best Things to Do in Cabo San Lucas in September
September brings specific advantages to Cabo. The warmest water of the year opens up exceptional snorkeling and diving conditions, while sea turtle nesting season and the return of playful sea lion pups create wildlife encounters that other months can't offer.
September's quieter pace means more space on the sand and shorter wait times for popular activities. Early morning hours are perfect for desert adventures, and midday heat makes water activities feel like exactly what you need.
We've put together a full guide covering the top activities: Things to Do in Cabo San Lucas in September.
Our Top Pick to Enjoy the Best of Cabo San Lucas
September's pattern of warm mornings, hot afternoons, and calm ocean conditions calls for a day that moves between desert adventure and beachside relaxation, which is exactly what the Tierra Sagrada Beach & Adventure Park All Inclusive delivers across six hours at Cabo's hidden oceanfront sanctuary.
The morning heat works in your favor when you start with ATV and UTV rides across rugged Baja terrain, trek the shoreline on camels, or cruise scenic trails on e-bikes before the midday peak. Then you shift to the Beach Club, where a pool, jacuzzi, hammocks, and firepits let you settle into the afternoon shade with unlimited cocktails, a buffet lunch with authentic Baja cuisine, and beach games like volleyball and spikeball.
Kids explore gem mining, a petting zoo, burrito rides, and a mini zipline, while adults enjoy tequila and mezcal tastings, an art studio, and cooking lessons. Surfers can hit nearby Cerritos Beach. Everything is included: transportation, meals, drinks, and all activities, so September's weather becomes something you work with, not around.
You're Ready for Cabo San Lucas in September
Now you know what Cabo weather looks like in September. You can plan around the temperatures, prepare for rain if needed, and time your activities to match the conditions. The warmest water of the year, thriving marine life, and spacious beaches give September advantages that the peak season doesn't offer. Whether you're here for the ocean, the wildlife, or the adventures, this month has something worth trying.
Ready to make it happen? Browse our full selection of Cabo San Lucas tours and find the right tours for your travel style. The best tours fill up fast, especially when September's quieter pace means more personalized group sizes, so book ahead and show up ready.