How Early Should You Leave Slough for Your Flight? Heathrow, Gatwick, Luton & Stansted
A realistic guide to what time to leave Slough for every London airport — drive times, check-in rules, peak-hour traffic and a simple leave-by table.
Leave too late and you're sprinting to the gate. Leave too early and you're paying for overpriced coffee for two hours. Here's how to work out exactly when to leave Slough for your flight.
The Simple Rule
Work backwards from your departure time:
- Be at the airport 2 hours before a short-haul flight, 3 hours before long-haul.
- Add the drive time from Slough (table below).
- Add a buffer of 15–30 minutes for traffic, more on Friday afternoons and bank holidays.
Leave-By Table from Slough
| Airport | Typical drive | Leave before short-haul | Leave before long-haul |
|---|---|---|---|
| Heathrow T5 | ~15 min | 2h 30m | 3h 30m |
| Heathrow T2, T3, T4 | ~20–25 min | 2h 45m | 3h 45m |
| Luton | ~45–55 min | 3h 15m | 4h 15m |
| Gatwick | ~55–70 min | 3h 30m | 4h 30m |
| London City | ~55–75 min | 3h 00m* | — |
| Stansted | ~75–90 min | 4h 00m | 5h 00m |
*London City's check-in times are shorter than most airports, but always check your airline's rules.
When Traffic Changes Everything
From Slough, almost every airport run uses the M4 and the M25. The worst times are weekday mornings between 7am and 9:30am, Friday afternoons and the start and end of school holidays. A 4am departure to Gatwick can take 50 minutes; the same trip at 5pm on a Friday can take well over 90.
Check Your Airline's Cut-Offs
Low-cost airlines at Luton, Stansted and Gatwick often close bag drop 40 minutes before departure and are strict about it. If you have hold luggage, the bag-drop deadline matters more than the departure time.
Let Us Plan It
When you book with Local Slough Taxi, give us your flight time and we'll suggest a pickup time based on the route and time of day. See fares for Heathrow, Gatwick, Luton, Stansted and London City, or call 01753 572121.
