San Francisco → London flights
San Francisco to London fares show a $323 median over 30 days; book near the low end, as roughly a quarter of fares climb to $384 or more.
SFO–LHR fares hover near $323 — but a $384+ tail lurks
Key takeaways
- $323 median fare across 30 daily snapshots — a reasonable benchmark for this route.
- Bottom quartile sits at $323, meaning the cheapest fares aren't rare outliers — a large share of days land right at the median.
- Top quartile jumps to $384+, and the high snapshot hit $423, so late or inflexible searches carry real upside risk.
- 41% spread between low and high — a wide enough range that timing your search matters more than usual on this route.
- Low of $299 shows sub-$300 fares are achievable, but they weren't the norm across the sample.
30-day price trend
See full numbers and stats on the SFO → LHR price history page.
The full picture
The 30-day snapshot for SFO–LHR shows a median fare of $323, with a floor of $299 and a ceiling of $423 — a 41% spread from low to high. That's a meaningfully wide range for a major transatlantic route, and it suggests fare volatility is driven more by demand fluctuations or booking-class availability than by a stable, predictable pricing floor. Notably, the 25th percentile ($323) sits right at the median, which tells us cheaper fares aren't isolated flukes — a solid chunk of the sampled days cluster near that $320s range before prices stretch upward into the $384–$423 territory in the top quartile.
We don't have day-by-day booking-window data (how far in advance each fare was purchased relative to departure), so we can't responsibly claim a specific number of weeks or days out is optimal — that would be guessing dressed up as insight. What the data does support is a general strategy: since a large share of observed fares land at or near the median, a fare quoted at $323 or below is a good one to act on for this route, while anything pushing past $384 is trending into the expensive quartile and may be worth waiting out or comparing alternate dates.
We don't have carrier-level data in this sample, so we can't speak to whether a specific airline is driving the cheaper fares or the spikes — that's a gap worth flagging rather than papering over. The honest takeaway: with a 41% spread and no visible day-of-week or carrier pattern in the data provided, this route rewards flexible, opportunistic booking more than a fixed calendar rule. Treat $323 as your target, treat anything near $299 as a genuine deal, and treat $384+ as a signal to check other dates before committing.
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Related travel pages
Why we regenerated this article: Top quartile ↑ 15% ($333 → $384). We only rewrite when the underlying price index actually moves — stable weeks keep the previous take.
AI-authored from this route's 30-day price index. Article last regenerated Sep 19, 2026. Fares shift continuously — confirm at booking.