How reliable is Marechal Cunha Machado International Airport?
Flights from SLZ avoided significant airline-controlled delay in 87% of 33,536 flights in official ANAC history — and weather is calmest in Sep. Here’s the full picture before you book.
Reliability score
on-time, cancellations & delays
Weather favorability
year-round climate
Origin-airport operations
What the airline-controlled delay record at SLZ looks like
Avoided 15+ min controlled delay
across 33,536 flights
Source: ANAC VRA · data through 2026-06-25. Origin-grouped, cause-attributed operational history; it is not a direct departure-punctuality measure or a guarantee for any flight.
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Weather by month
When the weather works for you at São Luís
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 100/100 favorability
Roughest month
Most disruptive — thunderstorms, low visibility & fog · 95/100 favorability
The read on SLZ
What the numbers say about flying through Marechal Cunha Machado International Airport
Across official performance history, flights from São Luís avoided significant airline-controlled delay about 87% of the time over 33,536 flights. That's one of the more dependable operational records you'll see. Pair it with a moderate cancellation rate of 1.8%. When a departure does run late, the typical delay is around 0 minutes.
On weather, São Luís is an unusually calm-weather airport year-round. September is the calmest stretch for flying, scoring 100 out of 100 for favorable conditions, while March is the most disruptive at 95, driven mainly by thunderstorms and low visibility & fog. The year is relatively steady, so no single month stands out as one to avoid on weather alone.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to São Luís, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about SLZ
- How reliable is Marechal Cunha Machado International Airport (SLZ)?
- Flights from São Luís avoided significant airline-controlled delay roughly 87% of the time across 33,536 flights of official history — one of the more dependable operational records you'll see. The cancellation rate runs about 1.8%. It's advisory context, not a guarantee for any single flight.
- What is the best month to fly from SLZ for good weather?
- September has the calmest flying weather at Marechal Cunha Machado International Airport. March is the most disruptive, mainly from thunderstorms and low visibility & fog.
Planning a trip through São Luís?
Score real flights to and from SLZ on reliability, weather, and connection safety — not just price.