FOG post
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One foggy day years ago we had to circle the airport a number of times with a great view of downtown but the pilot couldn’t see the airport. Ended up in Hamilton and bussed back to Billy Bishop.
Today while at Cherry Beach Sports field I could hear the planes but could barely see them overhead.
So I asked ChatGPT- “How many flight per year are delayed or cancelled in and out of billy bishop airport due to fog.”
What the data actually shows
- The airport handles roughly ~98 flights per day (~36,000/year)
- About 16% of flights are delayed (all causes)
- About 2.4% are cancelled overall
That translates roughly to:
- ~5,500–6,000 delayed flights/year (all causes)
- ~850–900 cancelled flights/year (all causes)
How much of that is fog?
Fog is one of the main weather issues at Billy Bishop (because it sits right on Lake Ontario), but:
- Weather (fog, snow, wind, storms combined) is typically only a fraction of total delays.
- On a single dense fog day, about 86 flights were impacted (delays + cancellations combined)
A realistic yearly estimate for fog specifically
Toronto gets multiple fog events per year (especially fall + spring). If you scale that 86-flight example across typical fog days:
- ~5–15 significant fog days/year
- × ~50–100 affected flights per event

Rough estimate:
- ~300 to 1,200 flights/year impacted by fog (delayed or cancelled)
Important nuance
- Billy Bishop is more sensitive to fog than Pearson because:
- Short runway
- Strict operating hours (curfew)
- Limited ability to “wait it out”
- So fog disruptions can cascade into cancellations faster than at larger airports.
Bottom line
- Total delays/cancellations (all causes): ~6,000–7,000 flights/year
- Fog-related impacts (estimate): a few hundred up to ~1,000 flights/year
If you want, I can break this down by season (fall vs winter) or compare fog impact at Billy Bishop vs Pearson—that’s where the differences get really interesting.
Then I Ask ChatGPT about Fog.
Typical comparison (approximate)
- Billy Bishop: ~20–40 foggy days/year
- Pearson: ~10–20 foggy days/year
(Exact counts vary year to year, but Billy Bishop consistently leads.)
Practical impact
Even when both airports get fog:
- Billy Bishop is more operationally affected (short runway, stricter visibility minimums)
- Pearson can often keep operating in conditions that shut Billy Bishop down
Bottom line
If you’re choosing based on reliability in fog-prone seasons (spring/fall),

Pearson is generally the safer bet

Billy Bishop is more likely to see fog-related delays or cancellations
Maybe I’ll search snow issues next.
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