Route on-time record
GSP to BWI: most on-time flights and the best time to fly
Greenville/Greer/Spartanburg (Greenville-Spartanburg International Airport) to Baltimore (Baltimore/Washington International Thurgood Marshall Airport). 719 nonstop flights in Jun 2025 to May 2026, 89% arrived within 15 minutes and 1.5% were cancelled. The most reliable flight number was Southwest 3412 at 8:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
GSP → BWI
Greenville/Greer/Spartanburg to Baltimore: 719 nonstop flights a year
On time (12 months)
89%
Cancelled
1.5%
avg delay 8 min
Best time to leave
9 AM to noon
100% on time vs 69% 3 to 6 PM
Most reliable airline
Southwest
87% chance on time
Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · Southwest 3412
8:00 AM → 9:30 AM1h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
92%
chance on time
- On time (history)
- 94%
- Cancelled
- 0.0%
- Avg arrival delay
- 6 min
- Arrived on time 94% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- Short track record (33 flights), so its score leans on the airline's record at this hour.
Limited track record · 33 flights
Find Southwest 3412 fares Opens this date on Aviasales#2 · Southwest 643
12:25 PM → 2:00 PM1h 35m nonstop
Local times, typical schedule. Last flown 2026-05-30.
90%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 2 min
- Arrived on time 100% of the time (8 flights, Jun 2025 to May 2026).
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 643 fares Opens this date on Aviasales#3 · Southwest 2243
8:10 AM → 9:45 AM1h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31.
90%
chance on time
- On time (history)
- 91%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 91% of the time (55 flights, Jun 2025 to May 2026).
- Never cancelled in 55 scheduled flights.
- Short track record (55 flights), so its score leans on the airline's record at this hour.
Limited track record · 55 flights
Find Southwest 2243 fares Opens this date on Aviasales#4 · Southwest 2244
1:50 PM → 3:20 PM1h 30m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 3029; its record covers all of them.
89%
chance on time
- On time (history)
- 91%
- Cancelled
- 0.0%
- Avg arrival delay
- 8 min
- Arrived on time 91% of the time (80 flights, Jun 2025 to May 2026).
- Never cancelled in 80 scheduled flights.
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
Moderate track record · 80 flights
Find Southwest 2244 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines87%
719 flights · 89% on time as flown · 1.5% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM96%
319 flights · avg delay 3 min
- 9 AM to noon100%
46 flights · avg delay 0 min
- Noon to 3 PM92%
140 flights · avg delay 6 min
- 3 to 6 PM69%
125 flights · avg delay 22 min
- 6 to 9 PM80%
89 flights · avg delay 16 min
Best day: Wednesday (89%). Worst: Monday (80%).
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Late-arriving aircraft54%
- Air traffic control and airport volume22%
- Airline (crew, maintenance, boarding)21%
- Severe weather3%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
GSP to BWI questions
- What time of day is best to fly GSP to BWI?
- 9 AM to noon: 100% of flights arrived on time, against 69% for departures 3 to 6 PM.
- Which airline is most on time from GSP to BWI?
- Southwest, with a season-adjusted 87% chance of operating and arriving on time over 719 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on GSP to BWI?
- July (76% on time); the best was January (91%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from GSP
- BWI to GSP (return)
- GSP to ATL 89%
- GSP to ORD 75%
- GSP to CLT 83%
- GSP to DFW 74%
- GSP to DCA 68%
- GSP to LGA 76%
- GSP to EWR 86%
- GSP to MIA 80%
- GSP to DTW 85%
- GSP to BNA 89%
- GSP to PHL 88%
- GSP to DEN 79%
Live status: FAA delays and ground stops